MOTOR VEHICLE POLLUTION IN AUSTRALIA

MOTOR VEHICLE
POLLUTION IN
AUSTRALIA
Supplementary Report No. 1
LPG In-Service Vehicle
Emissions Study
prepared by the
NSW Environment Protection Authority
for
Environment Australia
&
Federal Office of Road Safety
May 1997
GPO Box 594
Tel: +61 6 274 7111 Canberra ACT  2601
Fax: +61 6 274 7714 AustraliaACKNOWLEDGMENTS
Environment Australia commissioned the NSW EPA to undertake the LPG In-service Vehicle Emissions Study.
The Federal Office of Road Safety was responsible for ove rall financial and project management of the Study.
The NSW EPA Project Team wishes to acknowledge the considerable support given by a number of
organisations over the duration of the study. Particular thanks are extended to the following contributors:
· the thirteen householders who entrusted their private vehicles to the emissions
laboratories for testing;
· ALPGA,  for providing advice on technical matters, supplying information on the
LPG vehicle fleet characteristics and arranging industry support through the
coordination of its members;
· DASFleet, for providing new-model ‘replacement’ vehicles at nominal rates for use
by the private vehicle owners who agreed to let us test their cars;
· ELGAS Ltd., for supplying and delivering the test fuel (free of charge) to both
laboratories;
· NSW Taxi Council and the Victorian Taxi Council for assisting with arrangements
to test a variety of taxis from a number of the members;
· NRMA Limited, for providing comprehensive insurance coverage for all
‘replacement’ vehicles and  for the provision of roadside service coverage for
‘replacement’ vehicles in NSW;
· RACV Ltd, for the provision of roadside service coverage for all ‘replacement’
vehicles being driven in Victoria;
Other organisations who contributed to the project include:
· AGB McNair
· Boral Transport Maintenance Services (NSW)
· Gameco (NSW) Pty Ltd
· Parnell LPGas Systems Pty Ltd (Victoria)
· Environment Protection Authority (Victoria)
As well as the aforementioned contributions, everyone who became involved in the project - laboratory staff,
mechanics, industry bodies, contractors and  the people from other State and Federal government bodies - all
worked long and hard, often behind the scenes, to make this project a success.
To all of you, our sincere thanks.
Stephen Brown - Project Manager
Mustafa Kadayifci - Project Officer
Michael Faber - Project Officer.TABLE OF CONTENTS
EXECUTIVE SUMMARY
MAIN REPORT
1. BACKGROUND............................................................................................................ 1
2. INTRODUCTION......................................................................................................... 3
2.1 PRECEDING STUDIES TO THE LPG IN-SERVICE STUDY:.......................................................3
2.2 LPG STUDY OBJECTIVES..................................................................................................3
2.3 PARTIES INVOLVED..........................................................................................................4
2.3.1 Management ...........................................................................................................4
2.3.2 Contributors............................................................................................................5
3. STUDY OUTLINE ........................................................................................................ 6
3.1 SCOPE ............................................................................................................................6
3.2 PHASES OF THE STUDY ....................................................................................................6
3.2.1 Sample Design.........................................................................................................7
3.2.2 Vehicle Survey & Sourcing ......................................................................................9
3.2.3 Vehicle Processing, Testing and Servicing .............................................................10
3.2.4 Data Handling and Reporting................................................................................12
4. TEST FUEL................................................................................................................ 13
4.1 LPG AS A FUEL .............................................................................................................13
4.2 TEST FUEL USED ...........................................................................................................13
5. AUSTRALIAN DESIGN RULES ............................................................................... 14
5.1 BASELINE TEST CYCLE - EXHAUST EMISSIONS..................................................................14
5.2 EVAPORATIVE EMISSIONS MEASUREMENTS.....................................................................14
5.3 AUSTRALIAN DESIGN RULE (ADRS) LIMITS.....................................................................15
6. RESULTS.................................................................................................................... 16
6.1 INTRODUCTION .............................................................................................................16
6.2 FORMAT OF RESULTS.....................................................................................................16
6.3 CHARACTERISATION OF EXHAUST EMISSIONS BY VEHICLE CATEGORY VS ADR LIMITS .......17
6.4 MAINTENANCE OF VEHICLE FLEET .................................................................................18
6.4.1 Effectiveness of tuning on tailpipe emission levels.................................................18
6.4.2 Effect of tuning of individual vehicle categories.....................................................19
6.4.3 Cost of tuning........................................................................................................21
6.5 COMPARISON OF LPG VEHICLE EXHAUST EMISSIONS WITH SIMILAR MAKE AND MODEL PETROL
FUELLED VEHICLES TESTED IN THE NISE STUDY .................................................................216.6 CHARACTERISATION OF EVAPORATIVE EMISSIONS (SHED) ..............................................24
6.6.1 Comparison of LPG Evaporative Emissions to ADR Limits....................................24
6.6.2 LPG vs Dedicated Petrol NISE Study SHED results..............................................25
6.6.3 Observations regarding the high SHED results.....................................................25
6.7 COMPARISON OF INDIVIDUAL VEHICLES WITHIN EACH LPG VEHICLE CATEGORY................26
6.7.1 Private Vehicles ....................................................................................................26
6.7.2 Fleet Vehicles........................................................................................................28
6.7.3 Taxis .....................................................................................................................29
6.8 COMPARISONS OF LPG FUEL SYSTEMS ...........................................................................31
6.8.1 Open vs Closed Loop Fuel Management Systems...................................................31
6.8.2 Fixed vs Variable Venturi Fuel/Air Mixing ............................................................33
6.9 CASE STUDIES...............................................................................................................35
6.9.1 Incorrect Tuning of Vehicle....................................................................................35
6.9.2 Faulty Engine Management System (EMS) ...........................................................35
6.9.3 High SHED results................................................................................................36
6.9.4 Disconnected Vacuum Hose at LPG Fuel System Converter ..................................37
6.9.5 Incorrect parts.......................................................................................................37
7. FUEL CONSUMPTION ............................................................................................. 39
7.1 LPG FUEL CONSUMPTION COMPARED TO PETROL ...........................................................40
8. EFFECTIVENESS OF INSPECTION/MAINTENANCE SHORT TESTS............... 41
8.1 IM-240 TEST RESULTS ...................................................................................................42
8.2 SS-60 TEST RESULTS .....................................................................................................43
8.3 ASM-25/25 TEST RESULTS .............................................................................................44
8.4 IDLE TEST RESULTS .......................................................................................................45
8.5 HIGH IDLE TEST RESULTS ..............................................................................................45
8.6 SUMMARY OF SHORT EMISSION TEST CORRELATION RESULTS..........................................46
9. SUMMARY OF RESULTS AND OBSERVATIONS.................................................. 48
10. REFERENCES ......................................................................................................... 50
10.1 INFORMATION ON DEDICATED LPG FUELLED VEHICLES ................................................50LIST OF ILLUSTRATIONS
FIGURE 6-1: VEHICLE CATEGORIES IN “AS RECEIVED “CONDITION VS ADR LIMITS...................17
FIGURE 6-2(A): EFFECTS OF TUNING COMPARED WITH ADR27 ...............................................19
FIGURE 6-2(B): EFFECTS OF TUNING COMPARED WITH ADR37 ...............................................19
FIGURE 6-3: EMISSIONS FROM VEHICLE TYPE FOR EACH  POLLUTANT (LINES INDICATE ADR LIMIT)
20..................................................................................................................................
FIGURE 6-4: TUNING COSTS OF VEHICLE CLASS ....................................................................21
FIGURE 6-5: COMPARISON OF ADR27 LPG AND PETROL  FUELLED VEHICLES FOR BOTH PRE-TUNE
AND POST-TUNE. .........................................................................................................22
FIGURE 6-6: COMPARISON OF ADR37 LPG AND PETROL  FUELLED VEHICLES FOR BOTH PRE-TUNE
AND POST-TUNE. .........................................................................................................23
FIGURE 6-7: LPG VEHICLE SHED RESULTS.........................................................................24
FIGURE 6-8: SHED RESULTS, LPG VS PETROL (PRE AND POST TUNE) ....................................25
FIGURE 6-9: PRE AND POST-TUNE EXHAUST EMISSIONS FOR ADR27 PRIVATE VEHICLES ........27
FIGURE 6-10: PRE AND POST-TUNE EXHAUST EMISSIONS FOR ADR37 PRIVATE VEHICLES.......28
FIGURE 6-11: PRE AND POST-TUNE EXHAUST EMISSIONS FOR FLEET VEHICLES ......................29
FIGURE 6-12: PRE AND POST-TUNE EXHAUST EMISSIONS FOR TAXIS ......................................30
FIGURE 6-13: EMISSION REDUCTION FROM DIFFERENT SYSTEMS...........................................32
FIGURE 6-14: EMISSIONS FROM DIFFERENT VENTURI TYPES FROM ALL VEHICLES ...................34
FIGURE 7-1: FUEL CONSUMPTION FOR VEHICLE CATEGORIES PRE-TUNE AND POST-TUNE SHOWN. 39
FIGURE 7-2: LPG FUEL CONSUMPTION COMPARED TO PETROL ..............................................40
FIGURE 8-1: IM-240 VS ADR TEST RESULTS ........................................................................42
FIGURE 8-2: SS-60 VS ADR TEST RESULTS ..........................................................................43
FIGURE 8-3: ASM-25/25 VS ADR TEST RESULTS ..................................................................44
FIGURE 8-4: IDLE VS ADR TEST RESULTS ............................................................................45
FIGURE 8-5: HIGH IDLE VS ADR TEST RESULTS....................................................................46GLOSSARY
ADR Australian Design Rule
ADR27 Australian Design Rule on Emission Control for Light Vehicles. For this report, ADR27
incorporates 27A, 27B and 27C as well as the original ADR27.
ADR37 Australian Design Rule (ADR37/00) on Emission Control for Light Vehicles
ADR37/01 The modified ADR37, due to be phased in starting in 1997
ALPGA Australian Liquefied Petroleum Gas Association
Blend Study A study commissioned by the EPA to determination of an LPG Certification Test Fuel”
Closed Loop An EMS that has the ability to analyse the exhaust gases from each piston stroke (through
the Oxygen sensor), adjusting the amount of fuel delivered to the engine for optimum
engine efficiency and stoichiometric level (see Attachment 5)
CO Carbon monoxide - a criteria pollutant
DASFleet Department of Administrative Services (Vehicle Fleet)
EA Environment Australia (the Federal Government's Environment Department)
EMS Engine Management System
EPA (Vic) The Environment Protection Authority of Victoria
FORS Federal Office of Road Safety
Gross Emitter A vehicle whose exhaust and/or evaporative emissions are considerably higher than the
relevant ADR limit
HC Hydrocarbons - a criteria pollutant
In-Service A motor vehicle other than new, that is currently registered
LPG Liquefied Petroleum Gas
LPG Vehicle For the purposes of this report, an LPG vehicle is one which is able to operate on either
LPG or petrol (dual-fuelled vehicle).
NISE Study the National In-Service Vehicle Emissions Study carried out by FORS (report titled
“Motor Vehicle Pollution in Australia”)
NOx Oxides of nitrogen - a criteria pollutant
NRMA National Roads and Motorists Association
NSW EPA New South Wales Environment Protection Authority
OEM Original Equipment Manufacturer
Open Loop the vehicle’s fuel system operation that delivers a “base” quantity of fuel which is
determined by engine speed, load and various electronic sensors. Exhaust gases are not
analysed (ie no Oxygen Sensor) and therefore, no adjustments are made to achieve
stoichiometry (see Attachment 5).
SHED Sealed Housing for Evaporative Determination.
Stoichiometric Ideal air/fuel mixture ratio for optimum engine efficiency and exhaust emissions
US EPA United States Environmental Protection Agency
Venturi There are two main types of mixer design:
Variable Venturi/Fixed Depression - This type of mixer uses an air valve design which
responds to the pressure difference created by the engine’s air flow requirements which is
controlled by the engine demand. This design utilises a relatively constant pressure drop to
the converter diaphragm to draw LPG vapour from cranking to full load.Fixed Venturi/Variable Depression - This mixer function creates a depression signal which
activates the converter diaphragm so as to deliver LPG vapour to the engine. The higher
the engine speed, the greater the depression  signal causing a greater gas flow to the
engine.
VKT Vehicle Kilometres Travelled. Usually expressed as the number of kilometres travelled per
year for a given set of vehicles.1
1. EXECUTIVE
SUMMARY
INTRODUCTION
With the increasing interest in alternative fuels and the growth in the LPG dual fuel automotive market, the LPG
In-service Vehicle Emissions Study (LPG Study) was undertaken to obtain emissions data from a sample of
LPG vehicles, as an adjunct to the National In-service Vehicle Emission (NISE) study. For logistical reasons
only petrol fuelled vehicles were tested under the NISE Study.
The NISE Study was completed by the Federal Office of Road Safety (FORS) in 1996.  Its principal objectives
were to evaluate the emission characteristics of Australia's passenger vehicle fleet and to investigate to what
extent pollution control systems deteriorated over time.  The results of the NISE Study were published in May
1996 as the Motor Vehicle Pollution in Australia Report, which is available from the Federal Office of Road
Safety.
The information on the emissions performance of LPG fuelled vehicles provided by the LPG Study is timely,
given the introduction from 1997 of tighter emission standards for petrol engined vehicles under Australian
Design Rule 37/01.  A review of ADR37/01 is also underway which, in part, aims to bring LPG fuelled vehicles
supplied by original equipment manufacturers within its scope, thus applying the same emissions standards to
both petrol and LPG fuelled cars.
Based on fuel usage figures supplied by the Australian Liquefied Petroleum Gas Association there are
approximately 400,000 vehicles of all types operating on LPG fuel in Australia. The number of actual registered
vehicles running on LPG is unclear, however it is estimated that approximately 3% of the total car fleet are dualfuelled (petrol/LPG) vehicles. These vehicles mainly comprise taxis, company fleet vehicles and private
vehicles.2
OBJECTIVES OF STUDY
The LPG Study was commissioned by Environment Australia to:
1. assess the magnitude and characteristics of emissions from the in-service LPG
vehicle fleet;
2. assess the potential for reductions in emissions through tuning;
3. compare those emission levels with similar vehicles operating on petrol; and,
4. evaluate the same short emission tests as conducted in the NISE Study for
possible inclusion in an inspection/maintenance program.
METHOD
The LPG study used the same test and vehicle processing protocols as the NISE Study.
Note: Cars tested in the LPG Study fall into two distinct groups that are generally treated
separately when analysing test data:
(a) Vehicles manufactured after January 1986 were built to comply with Australian Design
Rule ADR 37 and designed to run on unleaded petrol.  They generally have computercontrolled engine management systems, fuel injection, and are fitted with catalytic
converters.
(b) Cars made between 1974 and 1986 were designed to meet the less stringent ADR 27
and run on leaded petrol, do not have catalytic converters and generally have
carburettors rather than fuel injection systems.
A sample of 36 vehicles representative of the in-service LPG fleet were selected comprising 13 taxis, 10 fleet
vehicles and 13 private vehicles. The private vehicles were broken up into two subsets of seven vehicles
manufactured before 1986 and six manufactured after 1986. A further subset of vehicles was also subjected to
evaporative emission tests.
Most of the LPG vehicles tested used the more sophisticated "closed loop" technology, in which the fuel
delivery is continuously adjusted via a electronic feedback mechanism from the exhaust system.  Some vehicles,
mostly from the private fleet, used the older "open loop" technology, where there is no feedback and the air/fuel
ratio is manually set at a fixed value.3
Tests ranged from the complex and time consuming ADR certification test protocol (to which vehicle
manufacturers have to comply to supply vehicles to the Australian market), to the simplest checks which can be
done with minimal equipment at a repair shop. Each vehicle was tested both in its "as received" condition and
then again after tuning and minor repairs had been carried out. A 60/40 blend of propane/butane was used as the
test fuel. This is representative of that available in the Sydney and Melbourne metropolitan areas.
The tuning of vehicles was carried out as would be performed in a typical LPG repairer workshop to optimise
the vehicle for operation on LPG. The vehicle's air filter, spark plugs, points (if applicable) and oil were
routinely replaced however the focus was on repairing faults rather than replacing components.
KEY FINDINGS
The key findings of the LPG Study are listed below.
Emissions from LPG Vehicles
The emissions measured in the LPG Study were the four emissions regulated by the ADRs for petrol engined
vehicles.  These are exhaust emissions of carbon monoxide (CO), hydrocarbons (HC) and oxides of nitrogen
(NOx), and evaporative hydrocarbon emissions.
1. The majority of the LPG vehicles tested were able to meet the relevant ADR
exhaust emission limits for which the vehicles were designed.
2. Company fleet vehicles, on average, were the lowest emitters of CO and HC,
whilst private vehicles were the highest emitters. Average NOx emissions were
similar in all categories.
3. “Gross emitting” vehicles (those emitting many times above ADR limits) existed
across all categories.
4. Of the seven vehicles which underwent evaporative emission tests, only one
result was under the ADR limit. Those vehicles which failed the test emitted
from three to more than thirty times the limit. Both the LPG and petrol fuel
systems on a vehicle can contribute to evaporative emissions in a dual fuelled
vehicle. A speciation test conducted on one vehicle with high evaporative HC
emissions revealed that most of these emissions from this vehicle were derived
from the petrol fuel system.
5. Taxis and company fleet vehicles had an LPG fuel consumption rate of
approximately 18 L/100 km, whilst private vehicles operated at approximately
20 L/100 km. 4
Comparison with the Petrol Fleet (NISE Study results)
Similar make and model vehicles (Holden Commodores and Ford Falcons) from the NISE study have been used
when comparing the two fuel types. The difference in sample size between the two fleets (36 LPG vehicles, 129
Petrol vehicles) should be considered when comparisons are made between the two fuel types.  The key findings
in this comparison were:
1. The average evaporative emissions from LPG vehicles were more than twice
those of similar petrol vehicles from the NISE study.
2. The older (pre 1986) vehicles emitted slightly lower emissions of CO, HC and
NOx than NISE study petrol vehicles of similar make and model.
3. Newer (post 1986) vehicles also emitted less HC emissions, but slightly higher
CO and NOx, than NISE study petrol vehicles of similar make and model.
Effects of Tuning and Maintenance on Emission Levels
1. Tuning of both older (pre-1986) and newer (post-1986) vehicles with open loop
systems had a significant effect on reducing CO and HC emissions, while NOx
emissions increased (significantly for older and marginally for newer vehicles)
after tuning.
2. Whilst vehicles with open loop systems benefited substantially from tuning,
tuning had a minimal impact on CO, HC and NOx emissions from vehicles with
closed loop systems.
3. The pre-tune HC and CO emission levels on vehicles with closed loop systems
are significantly lower than vehicles with open loop systems.
4. Tuning did not have a significant effect on reducing evaporative emissions,
which on occasion were slightly higher after tuning.
5. The average cost  for tuning and minor maintenance regime undertaken in the
Study was $260, compared to $220 for similar vehicles in the NISE Study.
6. The fuel consumption of these vehicles was reduced by an average of twelve
percent after tuning.5
Short Emission Test Performance
A long-standing goal for governments seeking to reduce vehicle pollution has been to develop a short test that
reliably identifies high polluting vehicles.  To address this all vehicles in the NISE study were tested using a
number of short tests both prior to and after tuning.
The vehicles in the LPG Study were subjected to the same short tests.  The tests were:
IM-240 - Modified IM240 (Inspection & Maintenance) Test Procedure
This test is based on the first four minutes of the ADR37/00 certification test cycle and covers about 2km
total distance.  Emission results are converted to grams per kilometre for HC, CO and NOx.
ASM - Acceleration Simulation Mode Test Procedure (ASM2525)
The vehicle is driven on a chassis dynamometer at a speed of 40km/h.  Concentrations of raw exhaust
emissions of HC, CO and NOx are measured.
SS60 - Steady State Loaded 60km/h
The vehicle is driven on a chassis dynamometer at a constant 60km/h.  Emissions of HC, CO and NOx
are measured.
HIGH IDLE - Steady State High Idle Test Procedure
With the engine running at a speed of 2500 rpm the concentrations of raw exhaust emissions are
measured for HC and CO.
IDLE - Steady State Idle Test Procedure
With the engine running at idle speed (accelerator not depressed) the concentrations of raw exhaust
emissions are measured for HC and CO.
For each vehicle tested, the results of the short tests have been compared with the ADR certification test results
obtained from that vehicle.  The results of these comparisons follow.
1. The IM-240 test was found to correlate best with the ADR certification test.
2. The loaded steady state SS60 and ASM25/25 tests show a better correlation
with ADR certification test than the idle and high idle tests.6
SUMMARY
The study produced diverse information regarding the emission characteristics and the deterioration of pollution
control systems of the LPG in-service fleet. The study also highlighted deficiencies in the data available on the
make up and operation of the LPG fleet.  While these shortcomings did not affect this Study directly, they do
limit the capacity to use the Study results to accurately estimate LPG vehicle impacts on urban air quality.
The following points summarise the emissions picture for dual fuelled (petrol/LPG) vehicles when operated on
LPG:
· There were relatively small differences in exhaust emissions performance between the vehicles tested and
comparable vehicles operating on petrol
· Most of the vehicles complied with the exhaust emission standards applicable to comparable petrol engined
vehicles
· Most of the vehicles exceeded the evaporative emissions standards applicable to comparable petrol engined
vehicles by a wide margin
· Tuning and minor maintenance improved HC and CO emissions and fuel consumption on most vehicles, but
the benefits were not evenly distributed.  Tuning did not improve NOx or evaporative emissions.
· The in-service tests based on the use of a dynamometer were the most effective.1
MAIN REPORT
2. BACKGROUND
With the increasing need to find solutions for improved urban air quality, the potential
emission reductions from the in-service motor vehicle fleet (LPG, petrol and diesel
vehicles) has become a key element in environmental planners’ vehicle emission
control strategies.
The Federal Motor Vehicle Standards Act 1989 gives legal effect to the Australian
Design Rules (ADRs) as national standards for motor vehicles, covering vehicle
safety and emissions. The current standard covering ‘emission control for light
vehicles’, is ADR 37/00 which applies to the design and construction of all petrol
fuelled passenger cars (and derivatives). ADR 37/00 does not apply to fuels other
than petrol.
Australian Design Rules are frequently being reviewed. The review of ADR 37/00
has lead to modifications which have been incorporated in ADR 37/01 due to be
implemented in 1997. The primary objective of ADR37/01 is to reduce the emission
limits for new vehicles. One of the issues being considered for the next review of
ADR37 (ie ADR 37/XX), is the inclusion of emissions limits for new vehicles
manufactured to operate on alternative fuels such as LPG, as current in-service LPG
vehicles are not required to conform to any emission standards. The inclusion of
LPG emission limits is timely due to the increasing number of vehicles using LPG
and the growth in annual VKT of these vehicles.
The proposed Inspection & Maintenance program for NSW is currently being
designed to include emission testing of LPG vehicles as well as other alternative
fuelled vehicles. This program will require in-service vehicles to be tested for
emissions as part of a registration check and thus endeavouring to maintain
emission levels to those the vehicles was designed to meet.
Accurate data on the number of LPG vehicles in Australia is currently unavailable.
Estimates range between 135 000 (ABS data) to 400 000 (ALPGA estimate). This
discrepancy is possibly due to the different methods used in calculating the number
of vehicles operating on LPG.
The ABS’ figures are derived from vehicle registrations from each state (Although
NSW and the ACT are the only two states/territories that have accurate records on
the number of LPG vehicles). This data indicates that over 76 percent of LPG
vehicles are registered in NSW and Victoria.
The ALPGA’s figure of 400 000 is derived through fuel sales to the automotive
market. Due to many LPG vehicles (taxis, fleet vehicles etc.) travelling a high 2
number of annual kilometres (referred to as Vehicle Kilometres Travelled - VKT), and
the questions regarding the number of LPG vehicles outside NSW and the ACT, the
actual number of LPG vehicles could be anywhere between these two estimates.
Table 1: Estimates of the number of LPG vehicles in Australia
Source Yea
r
Passenge
r Vehicles
Total
Vehicles
1
‘LPG Motor Fuels’ paper presented at SAE
Conference  Motor Vehicles & the
Environment
199
3
- 250 000
ABS
2
 ‘Motor Vehicle Census Australia’ 199
3
43 000 60 500
ABS ‘Motor Vehicle Census Australia’ 199
5
98 500 136 500
ALPGA 199
6
- 400 000
Whilst the potential emission advantages from using LPG have been well
documented from studies overseas (US EPA, 1995; Hollemans et al., 1995), aftermarket vehicle conversions to dual fuel operation do not fully utilise this potential.
While some progress has been made with the introduction of closed loop fuel
management systems for new vehicles, concerns still exist regarding the emission
performance of the LPG in-service fleet.
                                                           
1
 LPG registered vehicles including trucks.
2
 NSW and the ACT are the only states/territories that keep accurate records on LPG conversions
and dual fuelled vehicles.3
3. INTRODUCTION
The NSW EPA was commissioned by EA in September 1995, to carry out a study
into the LPG in-service fleet using test procedures similar to those used in the NISE
Study.
EA utilised FORS’ experience from managing the NISE Study to provide overall
financial and project management for the study.  EPA (Vic) was in turn contracted by
NSW EPA to carry out a portion of the emission testing work.
A steering committee comprising EA, FORS, ALPGA, EPA (Vic) and NSW EPA was
assembled to oversee the study and ensure that the objectives were met.
3.1 PRECEDING STUDIES TO THE LPG IN-SERVICE STUDY:
The LPG In-Service Emission study was designed to complement the NISE Study
and utilise the information obtained from the LPG Blend Study.
LPG Blend Study:
In 1995, EA contracted the NSW EPA to evaluate the effect on vehicle exhaust
emissions and engine performance of different propane/butane LPG mixes. From
this information a standard LPG test fuel (consisting of a 50 percent propane and 50
percent butane mix) was recommended for use as a certification fuel for future ADR
testing requirements. Commercially available LPG blends range from a 60/40 mix of
propane/butane to 100 percent propane (refer 5.2 for the test fuel used in the Study).
NISE Study:
The NISE study conducted by FORS evaluated the emission characteristics of the
petrol in-service passenger vehicle fleet, assessed the effects of maintenance, and
determined the correlation between ADR Certification Tests and a number of short
emission tests.
LPG vehicles were originally included in the NISE study, however were later
excluded due to logistical difficulties in tuning to manufacturer's (ie petrol)
specifications (a requirement of the study).  The LPG Study required vehicles to be
tuned by a licensed LPG mechanic for optimised  operation using LPG rather than to
the vehicle manufacturer’s specifications.
3.2 LPG STUDY OBJECTIVES
The following objectives were identified and met:
i) To give an indication of the magnitude and characteristics of emissions
produced from the LPG in-service fleet.4
ii) To assess the potential for reductions in emissions from the LPG inservice fleet from regular maintenance; and
iii) To compare the emission levels from LPG vehicles to those operating on
petrol only. Comparisons to be made with the vehicles tested in the NISE
Study.
iv) To evaluate various short emission tests (compared to ADR Certification
Tests) for possible inclusion in an Inspection/Maintenance Program.
These tests were to be conducted using the same methodologies used in
the NISE Study.
3.3 PARTIES INVOLVED
The roles of the organisations that participated in the study are listed below:
3.3.1 Management
Environment Australia (EA
(
Responsible for the commissioning and funding of the study, and providing input into
the Steering Committee.
Federal Office of Road Safety (FORS)
Appointed by EA to provide financial management and to oversee the design and
implementation of the study in accordance with the agreed management plan.
FORS was also responsible for the publication of the final report.  A member and
contributor to the Steering Committee.
NSW Environment Protection Authority
The NSW EPA was responsible for initially proposing the Study for Federal funding
consideration.  As Project Managers the Motor Vehicle Testing Unit chaired the
Steering Committee and coordinated all aspects of the Study including design,
execution, data analysis and final reporting. The testing laboratory was responsible
for developing the test procedures, sourcing, tuning and testing 14 of the 36 vehicles
involved in the Study.
Environment Protection Authority (Victoria)
EPA (Vic) played a significant role in assisting the NSW EPA with the design, test
procedure development and execution of the Study. EPA (Vic) were sub-contracted
to the NSW EPA to carry out emission testing of 22 vehicles,  including vehicle
sourcing, tuning and data processing.
A member and contributor to the Steering Committee.5
Australian Liquefied Petroleum Gas Association (ALPGA)
The ALPGA provided advice on technical matters, information on the LPG vehicle
fleet characteristics and arranged industry support through the coordination of its
members.  The assistance and contribution in kind provided by the ALPGA was
received by both NSW and Victorian testing laboratories.  A member and contributor
to the Steering Committee.
3.3.2 Contributors
Boral Transport Maintenance Services (NSW) and Parnell LPGas Systems Pty Ltd
(Victoria)
Both companies provided licensed mechanics and replacement parts for tuning the
test vehicles, connected flexible hosing for test fuel cylinders and provided technical
advice to the testing laboratories.
ELGAS Ltd
Supplied and delivered all test fuel (free of charge) to each laboratory.
AGB McNair
As in the case of the NISE study, AGB McNair provided details on privately owned
LPG fuelled vehicles who, following a telephone interview, agreed to have their
vehicle participate in the study.
NSW Taxi Council & Victorian Taxi Council
Both Taxi Councils assisted in obtaining the much needed support from individual
taxi company operators to participate in the study by providing vehicles for testing.
DASFleet
Provided vehicles to both the NSW and Victorian laboratories to use as replacement
vehicles in exchange for LPG test vehicles.
Gameco (NSW) Pty Ltd
Provided LPG fittings to NSW EPA and technicians to connect and disconnect the
test-fuel LPG cylinder prior to and after testing.
NRMA Limited
As in the NISE study, the NRMA  provided insurance coverage for the replacement
vehicles used by EPA (Vic) and NSW EPA.6
4. STUDY OUTLINE
4.1 SCOPE
The study involved testing 36 vehicles ranging in make, model, age and usage that
were considered to represent the current LPG vehicle fleet.
Each vehicle tested was subjected to the same protocols used in the NISE study to
enable comparisons to be made with the petrol fleet. These protocols were:
· All vehicles underwent emission tests prior to, and following, a tune-up.
· The testing schedule included ADR37 (incorporating ADR27
3
), IM-240, SS60,
ASM25/25, High Speed Idle and Low Speed Idle emission tests (these tests are
described fully in Attachment 3).
· Seven of the vehicles were subjected to evaporative HC emission (SHED)
tests.
· The tuning of vehicles was restricted to the level of work received from a typical
commercial workshop within the LPG industry.
· Tests were conducted using commercially available fuel.
As previously stated, the NSW EPA was responsible for the design and
management of the study; however, the execution of the study was carried out in
partnership with EPA (Vic). Due to limited laboratory testing time available in NSW
and because the majority of LPG vehicles operate in Victoria, the Vehicle Emissions
Laboratory of EPA (Vic) was subcontracted to test 22 of the 36 vehicles.
Each laboratory (NSW and Victoria) was responsible for coordinating the collection
and return of test vehicles, tuning, emission testing and data collection as detailed in
the following section.
4.2 PHASES OF THE STUDY
The study was divided into the following phases:
i) Sample Design
ii) Vehicle Survey & Sourcing
iii) Vehicle Processing, Testing and Servicing
iv) Data Handling and Reporting
Throughout the study, the project team maintained, as practically as possible, the
methodologies and test protocols used during the NISE Study, including testing, data
handling and reporting.
                                                           
3 For the purposes of simplicity of presenting results, ADR27, A, B and C emission standards
are referred to as ADR27.7
4.2.1 Sample Design
The sample design phase ensured an appropriate representation (albeit limited in
terms of sample size) of the LPG fleet was tested. Following extensive discussions
with the ALPGA regarding the composition of the LPG fleet and review of fleet
statistics, vehicles were categorised into three groups - Private, Fleet and Taxis.
Table 2 lists which vehicles were tested at the NSW and Victorian laboratories.
Table 2: Type of Vehicles tested at specific laboratory
Vehicle Category
Laboratory Private Fleet Taxi Total
NSW 6 0 8 14
Victoria 7 10 5 22
Total 13 10 13 36
A search of LPG fleet statistics (vehicle age, make, model, kilometres travelled,
conversion kit types and fuel usage patterns) was undertaken by both NSW and
Victoria. Both States found that information regarding the composition of the LPG
fleet and fuel usage was poor and inaccurate. Therefore the design of the sample
was primarily carried out using fleet information (refer to page 8 for details) obtained
through detailed discussions with State representatives of the ALPGA. Data from the
Australian Bureau of Statistics and State transport agencies was used as
background information only.
Note:  The limited data on the LPG fleet held by government agencies is of concern
and has been noted in the key findings.
From this information, a comprehensive matrix of the LPG fleet encompassing
vehicle models and conversion kit types was developed and proportioned between
the two testing laboratories. The vehicles selected in the matrix were manufactured
by either Ford or Holden and having either  six or eight cylinder engines. This type of
vehicle is most suitable for LPG conversion (ie. a large vehicle with adequate space
to install an LPG cylinder).
The following points were also considered in developing the test-vehicle matrix (refer
to Table 3 and 4):
· ratios of different vehicle manufacturers and models
· conversion kit type - fixed or variable venturi
· range of vehicle ages and manufactured to meet the relevant emission
standards of ADR27,A,B,C or ADR37
· odometer reading
· maintenance history 8
Table 3: EPA Victoria’s test vehicle matrix.
Vehicle Source LPG Conversion Kit Type Holden Ford
Private   (7) Random sample      (7) 3 Pre-1986 &
4 Post-1986
Fleet     (10) Fixed Venturi*         (4) 1 3
Variable Venturi*    (6) 3 3
Taxi        (5) Fixed Venturi         (3) 1 2
Variable Venturi    (2) - 2
Table 4: NSW EPA’s test vehicle matrix.
Vehicle Source LPG Conversion Kit Type Holden Ford
Private    (6) Random Sample      (6) 3 Pre-1986 & 3
Post-1986
Taxi         (8) Fixed Venturi          (1) 1 -
Variable Venturi     (7) - 7
*  Refer to the Glossary for definitions of terms.
There is an emphasis on Taxi and Fleet vehicles manufactured after 1986. This is
because taxis and fleet vehicles both comprise a large portion of the fleet (refer to
information from the ALPGA below), perform a large portion of the total kilometres
travelled and are generally only a few years old.  All taxi and fleet vehicles tested in
this study were manufactured to meet the ADR37 emission standards.
Information on the current LPG vehicle fleet obtained from the ALPGA:
Taxis:
· 100 percent manufactured to ADR37 (post 1986)
· 85 percent manufactured by Ford
· 70 percent fixed venturi, 30 percent variable venturi conversion kit type
Fleet:
· 10 percent manufactured to ADR27 (pre 1986), 90 percent to ADR37 (post
1986)
· 60 percent Ford, 40 percent Holden
· Ford; 50 percent fitted with fixed venturi type conversion kits 50 percent
variable.9
· Holden; 40 percent fitted with fixed venturi type conversion kits; 60 percent
variable.
Private:
· 50 percent manufactured to ADR27 (pre 1986); majority fitted with variable
venturi type conversion kits.
· 50 percent manufactured to ADR37 (post 1986); majority fitted with fixed
venturi type conversion kits.
4.2.2 Vehicle Survey & Sourcing
Vehicles were sourced from the Sydney and Melbourne metropolitan areas. The
following methods were used to obtain vehicles.
Private Vehicles
The Private Vehicles were sourced through a random survey of householders in the
Sydney and Melbourne metropolitan region (which included the Central Coast in
NSW). A consultant, AGB McNair, gathered various data including the type of
vehicle, the owner’s name, address and a contact phone number via a random
telephone survey.  The owner was then contacted by way of an introductory letter
from FORS explaining the purpose of the study (see Attachment 1). The letter was
followed up with a telephone call from the respective laboratory, and arrangements
made to test the vehicle. The owners were provided with a replacement vehicle
whilst their vehicle was being tested which was generally for a period of three days.
Fleet Vehicles
Fleet vehicles were sourced through ALPGA members. A maximum of two vehicles
were selected from each company nominated by the ALPGA, to obtain a wide cross
section of the fleet. A mix of vehicle make, model, age and level of maintenance was
obtained.
Taxis
Taxis were sourced with the assistance of state Taxi Councils. A representative from
the Taxi Council explained the purpose of the testing to its respective members (taxi
companies) before being contacted by the relevant testing laboratory. A maximum of
three taxis were tested from each company in order to maximise the representation
of the taxi fleet. Additionally, each taxi company was requested to supply taxis with
odometer readings above 150,000 kilometres, which would be indicative of the fleet.
A hire fee was paid to the taxi operators for the use of their vehicles.10
4.2.3 Vehicle Processing, Testing and Servicing
Vehicle Processing
Prior to exchanging the owners vehicle with a replacement vehicle, an inspection
checklist and a vehicle handover form was completed and signed by both the owner
of the vehicle and a representative from the testing laboratory (see Attachment 4a
and 4b). Replacement vehicles for the taxis were not supplied to Taxi companies as
a hire fee was paid for the use of these vehicles.
Vehicles were returned to all owners with a full tank of LPG. The vehicle was
cleaned (inside and out) and any parts replaced during servicing (eg. spark plugs, air
filter, etc.) were returned to the owner with the vehicle.
The owners were also provided with a test sheet detailing:
· Any repairs/replacement/adjustments made as part of the tuning; and
· Results from the ADR 37/00 Exhaust Emission test, including fuel economy,
with a comparison to ADR 27 or ADR 37/00 limits the vehicle was required to
meet when new.
Vehicle Testing Procedure
Vehicles were tested both in the “as received” condition (Pre-Tune) and again after
servicing/tuning (Post-Tune). Tuning was carried out to optimise the vehicle’s
operation on LPG and not to vehicle manufacturers original specifications (as
performed in the NISE study).
All tests were carried out in accordance with the NISE Study test procedures.
However, to accommodate the specific differences of the LPG fuel system, minor
changes to fuel and vehicle preparation were necessary. The two most significant
changes are outlined below, (refer Attachments 2 and 3 for a full description of the
test procedures).
· The vehicles petrol tank was filled to 40 percent capacity using the  commercial
grade fuel used during the NISE Study, in accordance with ADR regulations.
The vehicle’s integral LPG fuel tank was bypassed  by closing the outlet tap on
the cylinder and connecting a flexible line from a point downstream of the tap to
an external cylinder containing the LPG test fuel. The external test cylinder was
secured in the boot of the vehicle behind the vehicle’s integral tank during all
phases of testing, including evaporative emission tests.
· The LPG was not heated during the diurnal stage of the SHED test; however
the petrol tank was heated in accordance with ADR specifications.
Each vehicle was subjected to the following tests and emissions recorded for both
the Pre and Post-tune condition as listed in Table 5.11
Table 5: Emission Tests Conducted in the Study
Name of Test Data Recorded
ADR37 Exhaust Emissions
(& includes the
corresponding ADR27 test)
CO, HC, NOx, CO2, Fuel
Consumption
ADR37 Evaporative
Emissions (& includes the
corresponding ADR27 test)
Total HC (only 6 of the 36
vehicles were tested for
evaporative emissions)
IM-240 CO, HC, NOx, CO2
Steady State Loaded
(SS60)
CO, HC, NOx, CO2
Acceleration Simulation
Mode (ASM-25/25)
CO, HC, NOx, CO2
Steady State (Idle) CO, HC, CO2
Steady State (High Idle @
2500 rpm)
CO, HC, CO2
Vehicle Servicing
Prior to testing, vehicles were inspected by the participating licensed LPG servicing
organisation to identify any problems and parts required for replacement. The vehicle
was then driven to the testing laboratory. The external test fuel cylinder was installed
and checked for leaks in readiness for the Pre-tune emission test.
Following Pre-tune emission testing, defective parts were replaced and the vehicle
tuned for optimum operation on LPG by the LPG servicing organisation. Tuning of
the vehicles was carried out using the LPG test fuel. The following parts were
routinely replaced on all vehicles:
· oil (using SG20W-50 oil) and oil filter
· air filter
· spark plugs (including adjusting gap)
· points (where fitted)
A “replacement parts” budget of approximately $150 was set for each vehicle.
Replacement of major components (eg catalytic converter) was carried out on an
individual assessment basis and within the total study fund limitations. In order to
reflect normal workshop practise, all major components were, where possible,
repaired or adjusted rather than replaced.
If a vehicle was supplied without a catalyst or with one inoperative, it was tested as
received. A new catalyst was then fitted (as part of the tune) and the vehicle
retested.12
The following items were inspected (and if necessary, replaced) during the pre-tune
inspection:
· Distributor condition and operation
· LPG stepper motor operation
· Ignition timing where applicable
· Hoses and other items of the fuel, electrical and emission control systems as
necessary.
The vehicle computer was also interrogated for faults.  All work carried out by the
licensed LPG servicing organisation was covered by the normal industry warranty
conditions.
4.2.4 Data Handling and Reporting
Emissions and fuel consumption results were calculated by each laboratory using
the appropriate hydrocarbon fuel fractions and fuel densities for the specified LPG
blend.
Once the results were verified by the respective laboratories, the NSW EPA collated
all results into one database for analysis.
Comparisons between the two fuel types (LPG and Petrol) was carried out using
relevant test results specific to Ford Falcons and Holden Commodores extracted
from the NISE data base. This sub set was further filtered so that only vehicles
manufactured during the same years as the LPG vehicles were included. While this
enabled comparisons to be made between the LPG Study results and the petrol
NISE Study results, the sample size of LPG vehicles was several times smaller than
the NISE petrol vehicles and should therefore be taken into account when viewing
results.13
5. TEST FUEL
5.1 LPG AS A FUEL
LPG has been used as a transport fuel in Australia since the 1970s, particularly in
taxis and vehicles operating indoors (forklifts). It is sold commercially to the
automotive market as a mixture of propane and butane (unregulated but is usually
either 100 percent propane or a 60/40 blend). The domestic market is regulated and
supplied with 100 percent propane. Small amounts of other gases (ethane,
propylene and butylene) are also occasionally included in the mixture.
At ambient temperature and pressure, LPG is a gas. Automotive LPG is converted to
liquid form by increasing the pressure inside the storage cylinders to approximately
eight atmospheres. LPG can also be converted to a liquid form through cooling,
although the high costs involved mean this method is rarely used.
LPG is stored in motor vehicles in its liquid form in a certified cylindrical pressure
tank. It is converted to gaseous form via the vehicles regulator before being supplied
to the gas-air mixer and directed into the combustion chamber of the engine.
Due to the supply and demand characteristics and the locations at which propane
and butane occur naturally, different States are supplied with varying proportions of
the gases within the automotive market. According to the ALPGA, the major
metropolitan cities on the east and south-eastern coasts of Australia, are usually
supplied with a 60/40 blend whilst rural areas in the east and most of the central and
western regions of Australia are supplied with 100 percent propane. However, these
blends vary according to current supply and demand.
5.2 TEST FUEL USED
The LPG Blend Study (referred to earlier in this report - see section 3.1) reported
that different variations in fuel blends had a significant effect on CO emission levels.
The report also recommended a mix of 50:50 be considered as a certification test
fuel. However, An LPG blend of 60 percent propane and 40 percent butane (60/40
blend) was chosen as the test fuel as this is the blend that is commercially available
in metropolitan NSW and Victoria.
All fuel used by both the NSW and Victorian Testing Facilities was supplied by
ELGAS. The LPG blend was prepared in new cylinders with a Propane/Butane ratio
tolerance of three percent (ie 60 to 63 percent by volume) propane to limit the
variation in vehicle emissions due to fuel composition.14
6. AUSTRALIAN DESIGN RULES
6.1 BASELINE TEST CYCLE - EXHAUST EMISSIONS
To demonstrate compliance with the relevant ADRs, exhaust emissions are
measured using a rolling road (chassis) dynamometer capable of simulating engine
load/speed conditions similar to those typically found in city driving conditions.
By “driving” the car on the dynamometer to a pre-determined and tightly controlled
cycle of acceleration, cruise and braking, together with idle periods to simulate
stationary traffic periods, an accurate and repeatable measurement of exhaust
emissions is possible. Several such test cycles are used around the world.
The ADRs  require that certification testing be done using a transient cycle, which
simulates driving a distance of 12 km at speeds up to 94 km/h. It is described fully in
Attachment 3. The current emission test procedure in use in Australia is the ADR37
drive cycle. This was the baseline test cycle used in both this study and NISE study
(where it was referred to as the FTP) and is the test to which vehicles must comply
when new.
6.2 EVAPORATIVE EMISSIONS MEASUREMENTS
In addition to tailpipe emissions, new vehicles are required to undergo a test to
measure evaporative emissions of hydrocarbons. These emissions are measured by
placing the vehicle in a sealed “room” and measuring the change in hydrocarbon
levels in the room’s atmosphere. The test is known as a “SHED” (Sealed Housing for
Evaporative Determination) test and is conducted in three phases.
Stage one - Diurnal Soak: simulates the effect of a cold vehicle (engine is cold to
touch) which is gradually heated as the temperature rises on a summer day. Since
the entire LPG fuel system operates under pressure, evaporative emissions from this
fuel system should be zero, regardless of the temperature of the fuel (the results
indicate that this may not be the case). Therefore only the petrol fuel tank was
heated (see Attachment 2 for details). After pre-conditioning by driving an ADR
cycle, the vehicle is “soaked” for a minimum of twelve hours in controlled ambient
conditions of 25 ± 5
o
C. Without starting the engine, the vehicle, with the test-fuel
cylinder connected and positioned in the boot, is moved into the SHED and the room
sealed. Evaporative emissions are calculated by the change in hydrocarbon levels
measured over a one hour period as the fuel in the petrol tank is heated from
approximately 16
O
C to 29
O
C.
Stage two - Drive Cycle: Following the diurnal soak, the vehicle is driven as per the
ADR test cycle and exhaust emissions measured. Immediately after the drive cycle
is completed, the vehicle is moved back into the SHED for the hot soak stage.15
Stage three - Hot Soak: This stage simulates the effect of parking a hot vehicle at the
end of a journey (from home to the shops, for example) or in case of the ADR at the
end of the drive cycle. The engine and fuel is hot, rather than cold as the case in
stage one. Evaporative emissions are calculated by the change in hydrocarbon
levels over a one hour period. The fuel tank (LPG or petrol) is not heated in this
stage.
The results for stage one and two are summed and recorded as the resulting grams
of hydrocarbons emitted by the vehicle (in grams per test).
6.3 AUSTRALIAN DESIGN RULE (ADRS) LIMITS
Not all vehicles manufactured prior to July 1976 are required to comply with emission
standards. However, from this date onwards, all petrol passenger vehicles (and
derivatives) were required, when new, to comply with a performance standard (ADR)
that set limits for exhaust emissions of:
· Hydrocarbons (HC)
· Oxides of Nitrogen (NOx)
· Carbon Monoxide (CO)
The Australian Design Rules also set maximum limits for evaporative emissions of
total hydrocarbons, including emissions from the fuel system, engine, paintwork, and
interior of the vehicle.
Cars tested in this study, were manufactured according to one of five Australian
Design Rules introduced since 1976:
· ADR27, 27A, 27B and 27C applied to vehicles manufactured from July 1976 to
January 1986.
· ADR37/00 covers the period from February 1986 to the present.
The emission limits set by these standards are shown in Table 6:
Table 6: Emission Limits for Passenger Vehicles
Standard HC
(g/km)
CO
(g/km)
NOx
(g/km)
Evap
(g/test)
ADR27 A,B &
C*
2.1 24.2 1.9 6.0**
ADR37 0.93 9.3 1.93 2.0
ADR37/01*** 0.26 2.1 0.63 2.0
* From 1/7/76 only
** From 1/1/82 onwards
*** Phased in from 1/1/9716
7. RESULTS
7.1 INTRODUCTION
Results, where practical, have been presented for each vehicle rather than as an
average to avoid fleet generalisation and to highlight the degree of scatter between
vehicles.
When viewing results, the following coding applies to identify individual vehicles,
their fleet category and the laboratory at which they were tested:
· Fleet (F) vehicles tested at Victorian lab (V): FV01 to FV10
· Taxi (T) vehicles tested at TV01 to TV05
Victorian (V) or NSW (N) lab: TN06 to TN13
· Private (P) vehicles tested at : PV01 to PV07
Victorian (V) or NSW (N) lab: PN08 to PN13
For the purposes of simplicity of presenting results, ADR27/A/B/C emission
standards are referred to as ADR27 in all illustrations.
7.2 FORMAT OF RESULTS
The results have been presented in such a way that initially show the emissions
performance of the LPG sample fleet as a whole, including the magnitude and
certain characteristics of exhaust emission levels, and to what extent did tuning
reduce the vehicles’ exhaust and evaporative emissions.
Following an overall picture, the data is then broken down into vehicle categories
(private (ADR27 and ADR37 vehicles), fleet vehicles and taxis). This method
identified any problems that may be isolated to certain sections of the LPG vehicle
industry.
Comparisons were also made with the NISE Study petrol fleet. By doing this,
questions regarding the LPG in-service vehicles’ performed in relation to the petrol
fleet could be investigated.
After tuning, several vehicles showed abnormal results. These results were used as
case studies to highlight some of the potential problems that can affect emissions on
LPG vehicles. These case studies investigated:
· Incorrect Tuning of Vehicle
· Faulty Engine Management System
· Disconnected Vacuum Hose
· High Evaporative Emissions17
7.3 CHARACTERISATION OF EXHAUST EMISSIONS BY VEHICLE CATEGORY VS ADR LIMITS
Vehicle category results have been presented in Figure 7-1 to illustrate the
characteristics of the LPG fleet while also showing the variation between vehicles
and the comparison to the relevant ADR limits. The horizontal lines on the figures
are the ADR limits applicable to the vehicle when new. The difference in the ADR
limits reflect the change to unleaded fuel and the advancement in emission control
technology.
Only the Private Vehicle category contained vehicles manufactured prior to and after
1986 and thus referred to both ADR27 and ADR37 limits. The Fleet vehicles and
Taxis were all manufactured after 1986 reflecting the nature of the current in-service
fleet and therefore only the ADR37 limits apply.
0
20
40
60
80
100
CO (g/km)
PRIVATE
ADR27
PRIVATE FLEET TAXIS
ADR37
0.0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
HC (g/km)
PRIVATE
ADR27
PRIVATE FLEET TAXIS
ADR37
0.0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
NOx (g/km)
PRIVATE
ADR27
PRIVATE FLEET TAXIS
ADR37
--------------------ADR27 Emission Standard                                ---------- ADR37 Emission Standard
Figure 7-1: Vehicle Categories in “as received “condition vs ADR limits18
All vehicles are shown in their “as received” or Pre-tune condition. Each bar
represents results from a specific vehicle tested and arranged in each category by
decreasing magnitude of CO emissions.
Key Findings
· Fleet vehicles are generally the lowest emitters of CO and HC while Private
vehicles are generally the highest emitters.
· The majority of vehicles tested recorded emission levels that were below the
ADR limits for which they were designed to comply.
· All categories had at least one “gross emitting” vehicle with at least one
pollutant far above the ADR limit.
7.4 MAINTENANCE OF VEHICLE FLEET
7.4.1 Effectiveness of tuning on tailpipe emission levels
The extent to which the vehicles were “tuned” varied slightly depending on the
conversion kit type and vehicle age; however the work constituted optimising the
engine for operation on LPG as would be performed in a commercial workshop
situation.
The following section evaluates:
1. The effectiveness of tuning vehicles in each vehicle category;
2. The costs associated with tuning each category and compares these to the
NISE study costs (ie similar make, model vehicles);
3. The effectiveness of tuning on an individual vehicle basis;
4. Specific vehicle faults by “Case Study” analysis to highlight the nature of some
of the repairs carried out during the study.
Figure 7-2(a) & (b) present a comparison of the vehicles tested against each criteria
pollutant. Separate figures are provided for ADR27 and ADR37 vehicles. 19
0
10
20
30
40
50
60
70
80
90
100
CO (g/km)
0.0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
HC or NOx (g/km)
CO (Pre & Post) HC (Pre & Post) NOx (Pre & Post)
denotes Mean Value ADR27 Limits
Figure 7-2(a): Effects of Tuning compared with ADR27
0
10
20
30
40
50
60
70
80
90
100
CO (g/km)
0.0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
HC or NOx (g/km)
CO (Pre & Post) HC (Pre & Post) NOx (Pre & Post)
denotes Mean Value ADR37 Limits
Figure 7-2(b): Effects of Tuning compared with ADR37
Key Findings:
· Tuning of vehicles in both ADR categories had a significant effect on reducing
CO and HC emissions.
· ADR27 vehicles exhibited a significant increase in NOx emissions after tuning
while ADR37 vehicles showed only a marginal increase.
· Tuning significantly reduced the number of “gross emitting” vehicles, and
reduced the scatter in the emission results.
7.4.2 Effect of tuning of individual vehicle categories
The following figures provide a break down of results by vehicle category to show the
degree of scatter and to highlight the variation in the effectiveness of tuning. For
individual vehicle results, refer to sections 7.7.1 for Private vehicles, 7.7.2 for Fleet
vehicles and 7.7.3 for Taxis.20
0
10
20
30
40
50
60
70
80
90
100
CO (g/km)
PRIVATE - ADR27
(Pre & Post)
FLEET
(Pre & Post)
TAXIS
(Pre & Post)
PRIVATE - ADR37
(Pre & Post)
0.0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
HC (g/km)
PRIVATE - ADR27
(Pre & Post)
FLEET
(Pre & Post)
TAXIS
(Pre & Post)
PRIVATE - ADR37
(Pre & Post)
0.0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
NOx (g/km)
PRIVATE - ADR27
(Pre & Post)
FLEET
(Pre & Post)
TAXIS
(Pre & Post)
PRIVATE - ADR37
(Pre & Post)
--------------------ADR27 Emission Standard                                ---------- ADR37 Emission Standard
Figure 7-3: Emissions from Vehicle Type for each
Pollutant (lines indicate ADR limit)
Key Findings:
· Results from the Taxi and Fleet categories were reasonably consistent,
although some outliers were apparent. Emissions from the Private vehicle
category were inconsistent.
· Private vehicles exhibited a significant improvement in CO and HC emissions
after tuning and a slight worsening of NOx emissions. Apart from one or two
taxis and fleet vehicles, there was little change in emission levels from tuning
for these categories. This may be due to the dominance of closed-loop fuel
management systems in these two categories.
· Overall, the effect of tuning was to reduce the “gross emitting” vehicles of each
category. This trend did not hold true for NOx emissions from ADR27 vehicles.21
7.4.3 Cost of tuning
A parts budget and a labour budget of $150 each was set for each vehicle. However,
due to the poor condition of some of the vehicles and an initial underestimation of
labour costs, the budget was not always adhered to. Ultimately the average cost of
tuning, including parts and labour, was approximately $260. This consisted of:
· Parts:- $121 average for NSW EPA and $30 for EPA Victoria
· Labour:- $220 average for NSW EPA and $180 for EPA Victoria
The difference in the average cost of parts between testing facilities stemmed from
several vehicles tested by the NSW EPA which required replacement of expensive
parts (ie catalytic converters, EGR valves and Oxygen Sensors).
The labour charge included the mechanics travel time to the testing facility, thereby
inflating the fee normally charged for a typical workshop tune.
Figure 7-4 shows the individual costs incurred by each vehicle, the average for each
vehicle category and the comparison to the NISE Study.
$ 0
$ 200
$ 400
$ 600
$ 800
$ 1000
$ 1200
PRIVATE
(ADR27)
PRIVATE FLEET TAXIS
(ADR37)
NISE Vehicles
(Petrol)
denotes Mean Value
Figure 7-4: Tuning Costs of Vehicle Class
· Tuning of ADR27 Private vehicles and Fleet Vehicles averaged ~$240 per
vehicle whilst ADR37 Private vehicles and Taxis averaged ~$300 per vehicle.
· The NISE Study average was ~$210
7.5 COMPARISON OF LPG VEHICLE EXHAUST EMISSIONS WITH SIMILAR MAKE AND MODEL
PETROL FUELLED VEHICLES TESTED IN THE NISE STUDY
Qualification:
· As mentioned in section 4.2.4, only Ford Falcons and Holden Commodores
were tested in this study. To provide a comparison between this study and the
NISE Petrol Vehicle Study, Ford Falcons and Holden Commodores of the same 22
make and model (1982-1993) have been extracted from the NISE database.
Although the LPG sample size is small, the method used enables a simple and
practical comparison between the two vehicle fleet types.
· Vehicles in the NISE study were all privately owned while the LPG study
contained a high proportion of commercial (fleet/taxi) type vehicles. These
vehicles would generally be regularly maintained.
· The average odometer reading for LPG vehicles was ~150 000 km but only
~130 000 km for the NISE vehicles. This is due to the large portion of taxis in
the LPG sample.
The vehicles have been grouped according to the relevant design standard. Figure
7-5 shows the emissions (both pre-tune and post-tune) for LPG vehicles compared
to petrol vehicles manufactured to the ADR27 standards. Figure 7-6 shows the same
comparison but for ADR37 vehicles. All three criteria pollutants are shown for both
ADR categories.
0
20
40
60
80
100
CO (g/km)
PRE-TUNE
LPG Petrol
POST-TUNE
LPG Petrol
ADR27 Limit (24.2 g/km) denote Mean Values
0
2
4
6
8
10
HC (g/km)
PRE-TUNE
LPG Petrol
POST-TUNE
LPG Petrol
ADR27 Limit (2.1 g/km) denote Mean Values
0
1
2
3
4
5
NOx (g/km)
PRE-TUNE
LPG Petrol
POST-TUNE
LPG Petrol
ADR27 Limit (1.9 g/km) denote Mean Values
Figure 7-5: Comparison of ADR27 LPG and Petrol
Fuelled Vehicles for both Pre-tune and Post-tune.23
0
20
40
60
80
100
CO (g/km)
PRE-TUNE
LPG Petrol
POST-TUNE
LPG Petrol
ADR37 Limit (9.3 g/km)
denote Mean Values
0
1
2
3
4
5
6
HC (g/km)
PRE-TUNE
LPG Petrol
POST-TUNE
LPG Petrol
ADR37 Limit (0.93 g/km) denote Mean Values
0.0
1.0
2.0
3.0
4.0
NOx (g/km)
PRE-TUNE
LPG Petrol
POST-TUNE
LPG Petrol
ADR37 Limit (1.93 g/km) denote Mean Values
Figure 7-6: Comparison of ADR37 LPG and Petrol
Fuelled Vehicles for both Pre-tune and Post-tune.
Key Findings:
· ADR27 LPG vehicles emit  lower exhaust emissions than similar petrol vehicles
for all three pollutants in a Pre-tune state.
After tuning, NOx emissions from LPG vehicles are greater than petrol vehicles,
whilst, for CO and HC, LPG vehicles have lower mean values.
· ADR37 LPG vehicles were marginally higher for CO and NOx emissions for the
Pre-tune test, whilst there was little change in HC emissions.
While a small decrease in NOx emissions was recorded following tuning of
petrol vehicles, NOx emissions from LPG vehicles increased. CO and HC
emissions were reduced for both LPG and petrol vehicles after tuning.
· Both the LPG and petrol vehicle sample contain “gross emitting” vehicles and
generally a large spread in results.24
· Tuning reduces the proportion of high emitting vehicles for both LPG and
Petrol.
7.6 CHARACTERISATION OF EVAPORATIVE EMISSIONS (SHED)
A sub set of seven vehicles were subjected to the SHED test, comprising three
private, two taxis and two fleet vehicles.
7.6.1 Comparison of LPG Evaporative Emissions to ADR Limits
The ADR37 limit for evaporative emissions is two grams per test and the ADR27 limit
is six grams. Figure 7-7 illustrates the Pre and Post-tune SHED results.
0
10
20
30
40
50
60
70
82 Falcon
86 Falcon
92 Falcon
92 Falcon
93 C'dore
94 Falcon
95 Falcon
VEHICLE DATA
HC (g)
Pre-tune Post-tune
ADR 27 Emission Standard (6g)
ADR 37 Emission Standard (2g)
Figure 7-7: LPG Vehicle SHED Results
Qualification:
· The method used for determining evaporative emissions does not identify the
origin of those emissions. On an LPG vehicle, the SHED result is derived from
both fuels. A speciation test is required to determine the specific fuel origin of
these emissions.
· Only one vehicle, a 1982 Ford Falcon, was manufactured prior to 1986 and
required to meet the ADR27 limit. All the others were manufactured after 1986
and required to meet the lower ADR37 limit.
· Six of the seven vehicles tested were Ford Falcons which may bias the result.
Further tests using a larger proportion of Holden Commodores is required
before results can be compared between vehicle manufacturers.
Key Findings:
· Apart from the 1993 Commodore and a 1992 Falcon Pre-tune test, all results
were well above the ADR limits. More importantly is the high degree of
exceedence.25
· The age of the vehicle does not influence the result. Rather the results are
scattered, ranging from three, to an exceptionally high 62 grams across the
various year models.
· Emissions were often higher after tuning. No explanation is given for this.
7.6.2 LPG vs Dedicated Petrol NISE Study SHED results
Ford Falcons and Holden Commodores of the same age bracket (1982-1993) were
extracted from the NISE study for comparison. The results from both SHED test
studies are illustrated in Figure 7-8.
0
10
20
30
40
50
60
70
80
90
HC (g/test)
Pre-tune Post-tune
PETROL LPG
Pre-tune Post-tune
denote Mean Values
ADR37 Limit
ADR27 Limit
Figure 7-8: SHED results, LPG vs Petrol (Pre and Post tune)
Key Findings:
· Evaporative emission results from dedicated petrol vehicles, whilst exceeding
the ADR limits, are generally lower than the LPG vehicles.
· Both  petrol and LPG vehicle evaporative emissions are varied and range from
below ADR limits to over 30 times the limit.
· The effect of tuning has a marginal benefit on lowering the emissions for LPG
fuelled vehicles.
· The Post tune mean values obtained for the  LPG vehicles were more than
twice those of the petrol vehicles.
7.6.3 Observations regarding the high SHED results
If an LPG vehicle operates almost entirely on LPG, the vehicle’s secondary fuel
system (in this case, the petrol system) can deteriorate (hoses drying out, petrol
going ‘off’ etc.) if the fuel is not ‘flushed’ through the system on a regular basis. The
result can be excessive evaporative emissions from this system.
It is not clear why these evaporative emissions were so high or where they originate
from. It is clear, however, that faults in either fuel system (LPG or Petrol) can have a 26
large impact on the magnitude of evaporative emissions. Some possible LPG vehicle
faults are outlined below. For more details about petrol evaporative emissions, refer
to the NISE report.
Faulty Fuel Filler Cap:
The main cause for evaporative emissions noted in the NISE study was a faulty fuel
filler cap. This could also be a major cause of LPG vehicle evaporative emissions.
Carbon Canister Damaged or Disconnected:
As carbon canisters are only used to collect petrol vapours from the fuel tank, they
may not be included in regular servicing schedules (for both LPG and petrol fuelled
vehicles) and therefore any damaged canisters would not be detected or repaired.
Also, the canister may be mistakenly de-activated or disconnected when converting
the vehicle to LPG operation. As a result, any residual fuel remaining in the petrol
tank will be allowed to vent directly to atmosphere.
Leaking Gas Lines:
Several vehicles were found to have LPG fuel line leaks around the LPG cylinder
connection. Whilst any detectable leaks were repaired before testing, there is a
possibility that other leaks were undetected and not repaired. As the system is under
pressure even a minor leak would produce a high SHED result.
7.7 COMPARISON OF INDIVIDUAL VEHICLES WITHIN EACH LPG VEHICLE CATEGORY
The following section provides details of individual vehicle results within each
category and discusses the effectiveness of tuning on emission performance.
7.7.1 Private Vehicles
The Private vehicle sample consisted of both ADR27 and ADR37 vehicles. A total of
thirteen private vehicles were tested of which seven were manufactured prior to 1986
(ADR27) and six after 1986 (ADR37). Table 7 provides a summary of the vehicles
tested at each of the testing facilities.
Table 7: Summary of where Private Vehicles were tested
Private Vehicles
Vehicle Standard: ADR-27  ADR-37
NSW EPA 3 3
EPA Victoria 4 3
Vehicles having to comply with ADR27 and ADR37 have been graphed separately to
enable comparisons with the respective limits. Figure 7-9 illustrates results from 27
vehicles manufactured to the ADR27 limit and Figure 7-10 illustrates ADR37 vehicle
results.
0
10
20
30
40
50
60
70
PV01 PV02 PV05 PV06 PN08 PN10 PN11
VEHICLE ID
CO (g/km)
Pre-tune
Post-tune
ADR Limit (24.2 g/km)
0.0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
PV01 PV02 PV05 PV06 PN08 PN10 PN11
VEHICLE ID
HC (g/km)
Pre-tune
Post-tune
ADR Limit (2.1 g/km)
0.0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
PV01 PV02 PV05 PV06 PN08 PN10 PN11
VEHICLE ID
NOx (g/km)
Pre-tune
Post-tune
ADR Limit (1.9 g/km)
Figure 7-9: Pre and Post-tune Exhaust Emissions for ADR27 Private Vehicles
Key Findings:- ADR27 vehicles.
· Except for PV05 (CO), PV02 (HC) and PV01 (NOx), these vehicles were below
or marginally above the ADR limit prior to tuning.
· Vehicles tuned to correct for the high Pre-tune CO results (PV05, PN10 &
PN11) and high HC result (PV02) had an increase in NOx emissions that
exceeded the limit (except PV05). This indicates that when tuning LPG
vehicles, one needs to be aware of the relationship between CO, HC and NOx
emissions and have the means to measure the effect of changing the vehicle’s
state of tune. The current focus of tuning would appear to be on lowering CO
and HC without adequate concern for the effect on NOx.28
0
10
20
30
40
50
60
70
PV03 PV04 PV07 PN09 PN12 PN13
VEHICLE ID
CO (g/km)
Pre-tune
Post-tune
ADR Limit (9.3 g/km)
0.0
0.5
1.0
1.5
2.0
2.5
3.0
PV03 PV04 PV07 PN09 PN12 PN13
VEHICLE ID
HC (g/km)
Pre-tune
Post-tune
ADR Limit (0.93 g/km)
0.0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
PV03 PV04 PV07 PN09 PN12 PN13
VEHICLE ID
NOx (g/km)
Pre-tune
Post-tune
ADR Limit (1.93 g/km)
Figure 7-10: Pre and Post-tune Exhaust Emissions for ADR37 Private Vehicles
Key findings :- ADR37 vehicles.
· ADR37 vehicles exceeded their appropriate ADR limits more often than ADR27
vehicles. This is particularly evident when making a comparison of the CO and
HC emissions. Rather than the odd one or two as with the ADR27 vehicles, all
six vehicles failed to meet the CO limit and five of the six vehicles failed to meet
the HC limit. The NOx exceedences are similar for both ADR categories.
· Tuning the vehicles significantly improved the emissions of CO and HC but
NOx emissions were on occasion increased above the ADR limit.
7.7.2 Fleet Vehicles
EPA (Vic) tested all ten Fleet vehicles selected in the sample. Exhaust emission
levels obtained from each of the vehicles are illustrated in Figure 7-11. Again both
the Pre and Post tune results are shown as well as the ADR37 limit.29
0
5
10
15
20
25
FV01 FV02 FV03 FV04 FV05 FV06 FV07 FV08 FV09 FV10
VEHICLE ID
CO (g/km)
Pre-tune
Post-tune
ADR Limit (9.3 g/km)
0.0
0.2
0.4
0.6
0.8
1.0
1.2
FV01 FV02 FV03 FV04 FV05 FV06 FV07 FV08 FV09 FV10
VEHICLE ID
HC (g/km)
Pre-tune Post-tune ADR Limit (0.93 g/km)
0.0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
FV01 FV02 FV03 FV04 FV05 FV06 FV07 FV08 FV09 FV10
VEHICLE ID
NOx (g/km)
Pre-tune
Post-tune
ADR Limit (1.93 g/km)
Figure 7-11: Pre and Post-tune Exhaust Emissions for Fleet Vehicles
Key Findings:
· Generally Fleet vehicle emissions could be classed as “low”. Four vehicles
exceeded ADR limits for any one pollutant prior to tuning.
· On average, tuning reduced both CO and HC emissions while increasing NOx
emissions.
· Vehicle FV01, which emitted more than twice the level of CO specified in
ADR37 did not respond significantly to tuning. A further test (results not
illustrated) was then conducted following replacement of the catalytic converter.
A significant reduction in emissions was recorded, confirming the catalytic
converter had failed.
7.7.3 Taxis
The NSW EPA tested eight taxis, and EPA (Vic) tested five. All were manufactured
to comply to ADR37 limits. Two of the Victorian taxis were also included in the 30
subset of vehicles subjected to a SHED test. Figure 7-12 illustrates Pre and Posttune exhaust emissions for each vehicle.
0
5
10
15
20
25
30
35
40
T V 0 1
T V 0 2
T V 0 3
T V 0 4
T V 0 5
TN06
TN07
TN08
TN09
TN10
TN11
TN12
TN13
VEHICLE ID
CO (g/km)
Pre-tune
Post-tune
ADR Limit (9.3 g/km)
100 g/km
0.0
0.5
1.0
1.5
2.0
2.5
T V 0 1
T V 0 2
T V 0 3
T V 0 4
T V 0 5
TN06
TN07
TN08
TN09
TN10
TN11
TN12
TN13
VEHICLE ID
HC (g/km)
Pre-tune
Post-tune
ADR Limit (0.93 g/km)
0.0
0.5
1.0
1.5
2.0
2.5
3.0
T V 0 1
T V 0 2
T V 0 3
T V 0 4
T V 0 5
TN06
TN07
TN08
TN09
TN10
TN11
TN12
TN13
VEHICLE ID
NOx (g/km)
Pre-tune
Post-tune
ADR Limit (1.93 g/km)
Figure 7-12: Pre and Post-tune Exhaust Emissions for Taxis
With the exception of vehicles TN08 and TN11, exhaust emissions of CO and HC
are below or just above ADR limits. NOx emission generally were below the limit
however the margin between the result and the limit was relatively small.
TN08 was found to have a defective catalytic converter, however the cause of the
defect was most likely due to the engine operating in an extremely rich condition and
the engine emission control equipment was disconnected. The Post-tune result
shows a dramatic improvement in both CO and HC results due to the reconnection
of the emission control equipment, engine tune and the installation of a new catalytic
converter. The relative emission performance of each repair is discussed further as a
case study in section 7.7.3.31
7.8 COMPARISONS OF LPG FUEL SYSTEMS
To explore the possible reasons for the variations between vehicle categories and
the large scatter of results, further analysis of the data was carried out. Specifically,
the characteristics of the LPG fuel system were evaluated in terms of the LPG
conversion kit type, the system of fuel management (Open or Closed loop) and the
method (fixed or variable venturi) used to convert the LPG and meter the fuel/air mix
prior to combustion.
7.8.1 Open vs Closed Loop Fuel Management Systems
In December 1993, the Australian Standard (AS1425-1989) was changed to require
that all closed loop vehicles converted to LPG fuel operation must continue to
operate with a closed loop management system. This requirement, combined with
improvements in LPG conversion kit technology, has resulted in the almost universal
introduction of closed loop fuel management systems. Figure 7-13 illustrates the
difference in emission levels of the vehicles using the two fuel management systems.
The effectiveness of tuning is also shown.
Table 8 lists the number of vehicles with open or closed loop systems in each
category. See Attachment 5 for a diagram of the Open and Closed Loop Engine
Management System.
Table 8: Summary of Engine Management Systems on Sample
Engine Managment System
Open loop Closed Loop
Private (ADR27) 7 -
Private (ADR37) 3 3
Fleet - 10
Taxi 1 1232
0
10
20
30
40
50
60
70
80
90
100
CO (g/km)
Pre-Tune Post-Tune Pre-Tune Post-Tune
Open Loop (ADR37) Closed Loop
Pre-Tune Post-Tune
Open Loop (ADR27)
0
1
1
2
2
3
3
4
4
HC (g/km)
Pre-Tune Post-Tune Pre-Tune Post-Tune
Open Loop (ADR37) Closed Loop
Pre-Tune Post-Tune
Open Loop (ADR27)
0
1
1
2
2
3
3
4
4
NOx (g/km)
Pre-Tune Post-Tune Pre-Tune Post-Tune
Open Loop (ADR37) Closed Loop
Pre-Tune Post-Tune
Open Loop (ADR27)
ADR27 Limit
ADR37 Limit
denotes Mean Value
Figure 7-13: Emission Reduction from Different Systems
Key Findings:
· The Pre-tune HC and CO emission levels on vehicles with closed-loop systems
are significantly lower than vehicles with open loop systems. However, both
open and closed loop vehicles on occasion exceeded ADR limits.
· Vehicles with open loop systems benefit substantially from being tuned (refer to
section  4.2.3 for scope of tuning) while little change is obtained from tuning
vehicles with closed loop systems.
· CO and HC emissions from ADR37 vehicles with open loop engine
management systems improved dramatically after tuning.  Conversely, NOx
emissions increased after tuning.33
7.8.2 Fixed vs Variable Venturi Fuel/Air Mixing
The two main venturi types (fixed and variable) used in LPG vehicles to mix the LPG
gas with intake air have been analysed separately to trends in vehicle emission
performance. Each venturi type can be present on both open or closed loop
systems. Table 9 lists the type of venturi used in the vehicles.
Figure 7-14 compares the venturi types with vehicle emissions and the effectiveness
of tuning.
0
10
20
30
40
50
60
70
80
90
100
CO (g/km)
Pre-Tune Post-Tune Pre-Tune Post-Tune
Fixed Venturi Variable Venturi
0.0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
HC (g/km)
Pre-Tune Post-Tune Pre-Tune Post-Tune
Fixed Venturi Variable Venturi
0.0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
NOx (g/km)
Pre-Tune Post-Tune Pre-Tune Post-Tune
Fixed Venturi Variable Venturi
ADR37 Limit denotes Mean Value
Figure 7-14: Emissions from different Venturi Types from all Vehicles34
Table 9: Venturi type used in test vehicles
Venturi Type
Fixed Variable
Private (ADR27) 2 4
Private (ADR37) 3 3
Fleet 5 5
Taxi 5 8
Key finding:
· Tuning can reduce emissions on vehicles fitted with either a fixed or variable
venturi and the effectiveness of the tune is not related to the type of venturi
used.35
7.9 CASE STUDIES
This section discusses some of the problems encountered with specific test vehicles
during the study. While the study aimed to test vehicles in the “as received”
condition, a number were rejected due to their poor condition, whilst others were
tested but tuning proved difficult. The following case studies highlights some of the
problems that were encountered.
7.9.1 Incorrect Tuning of Vehicle
Pre-tune test results from an EF Falcon  (TN06) indicated that the vehicle exceeded
(by four times) the CO limit, but was under the NOx and HC limit. After tuning, the
test results indicated the vehicle was emitting very high levels of CO and HC and low
NOx emissions - indicating incorrect tuning. Further investigation into the fault
identified a poor earth connection of the Engine Management System that resulted in
the vehicle continuously operating in a rich condition. The LPG system feeds off the
petrol system and as such any problem with either system can influence the
emissions when the vehicle is operating on LPG. The problem was identified and
rectified and the vehicle re-tested. Refer to Table 10 for summary of results.
The test results identified as “Post-tune with Earth Leakage” in Table 10 were
classified as a development test and were not included in the results reported in
other tables and figures in this report.
Table 10: Results from Earth-Leakage Post-tune test
CO HC NOx Fuel Con
(g/km) (g/km) (g/km) (L/100km)
Pre-Tune 13.79 0.37 0.72 17.42
Post tune with
Earth-Leakage
60.00 2.19 0.29 19.53
Post-Tune 7.24 0.22 0.88 16.87
This case study demonstrates how ineffective emission controls can be if incorrectly
installed and maintained. The benefits that can be achieved by this are highlighted
by the change in fuel consumption (in Table 10) after the fault had been repaired.
7.9.2 Faulty Engine Management System (EMS)
An EF Falcon (TN08) was received with the primary functions of the Engine
Management System disconnected. This resulted in the vehicle operating without
any form of fuel regulation, allowing excessive quantities of LPG to be delivered to 36
the engine. Consequently, the mixture was rich resulting in the emissions shown on
the first line of Table 11.
Table 11: Results of Vehicle with faulty EMS
CO HC NOx Fuel Con
(g/km) (g/km) (g/km) (L/100km)
Pre-Tune without EMS
connected
99.92 2.22 0.25 24.22
No EMS but Catalytic
Converter replaced
1.02 0.07 1.91 19.53
Re-tuned privately &
EMS reconnected
0.03 0.11 5.97 18.26
Inspection of the vehicle’s catalyst showed that certain sections of the catalyst had
been displaced, reducing exhaust flow and increasing back pressure on the engine.
As a consequence, the engine was required to work harder and consume excess
fuel. The vehicle was tuned and the catalytic converter replaced, however the EMS
was not re-connected in order to evaluate the effect of a new catalyst.
The installation of the new catalyst dramatically improved the CO emissions from
99.9 g/km to 1.0 g/km. However, the catalyst would soon fail again if the vehicle was
allowed to continue operating without the EMS connected.
The vehicle was returned to the owner for reconnection of the EMS and other
emission control systems. The vehicle was tuned privately and returned to the
laboratory for a second Post-tune test.
While CO and HC emissions were again reduced (CO from ~100 to 0.03 g/km and
HC from 2.2 to 0.11 g/km), NOx emissions increased to nearly three times above the
ADR limit. This result indicated that the vehicle was tuned to minimise CO emissions
without due consideration for the effect on NOx emissions.
Note: The data from the second Post-tune test has not been included in the test
averages reported elsewhere in this report.
7.9.3 High SHED results
Due to the nature of the LPG/Petrol dual fuel system, (ie a closed pressurised LPG
system and an open petrol system that permits vapours to be vented to atmosphere
through the carbon canister), any evaporative hydrocarbon emissions should
originate from the petrol system. To verify this assumption, the CSIRO was
requested to investigate the speciation of the hydrocarbon emissions to determine
their origins (ie LPG or petrol). This test was conducted on a 1992 Falcon, vehicle
PN06.
Analysis of the CSIRO results showed that evaporative emissions from both the Pretune and Post-tune SHED tests were derived predominantly from petrol. The37
Pre-tune and Post-tune emissions from this vehicle were 38 and 36 grams
respectively. Only one other vehicle recorded higher Pre-tune and Post-tune
emissions.
The high evaporative emission result caused primarily by petrol vapours raises
concerns regarding the use of dual fuel systems. Further testing is required to
establish if this is a common occurrence.
7.9.4 Disconnected Vacuum Hose at LPG Fuel System Converter
An ED Falcon (TN13) was delivered with a disconnected vacuum hose. This vacuum
hose connects the fuel control valve to the LPG fuel converter. Before the Pre-tune
test was conducted, the hose was mistakenly reconnected to the converter. The Pretune test is designed to test the vehicle in its original condition and therefore the
hose should have remained disconnected. This mistake remained undetected until
the vehicle was being tuned. The project team decided to conduct the Post-tune test,
and then carry out a repeat test with the vacuum hose disconnected; as should have
been in the Pre-tune test. The results of the additional test illustrate the effect the
vacuum hose has on the vehicle’s emissions performance. Table 12 summarises the
ADR37 results obtained for the vehicle.
Table 12: Effects of a disconnected vacuum hose
CO HC NOx Fuel Con
(g/km) (g/km) (g/km) (L/100km)
Pre-Tune with
Vacuum hose on
6.38 0.27 1.49 17.25
Post-tune with
vacuum hose on
8.13 0.33 1.13 17.80
Post-tune - vacuum
hose disconnected
83.59 1.80 0.16 22.70
Comparison of the two Post-tune results
With the hose disconnected, all emissions except NOx increased significantly. The
results highlight the importance of regularly inspecting the vehicle and carrying out
necessary maintenance to ensure the vehicle is in accordance with manufacturers
specifications.
Note: The Post-tune result with the vacuum hose disconnected does not form part of
the LPG results presented elsewhere in this report.
7.9.5 Incorrect parts
A '93 Falcon was found to be fitted with an incorrect diaphragm for the type of mixer
that was installed on the vehicle. After the Post-tune test, the diaphragm was
replaced with the correct type and the vehicle was tested a third time.38
The Pre and Post-tune results that were conducted with the incorrect diaphragm
fitted resulted in CO emissions of approximately 25 g/km for both tests. After
installing the correct diaphragm, CO emissions dropped to 4.9 g/km.
Further investigation into why the wrong diaphragm had been installed on this
vehicle revealed that, within the servicing industry, some issues that may be
considered to be more important than emissions control were:
· minimise backfiring; and
· improving fuel economy
It was also revealed that by fitting an incorrect diaphragm onto a vehicle running in
closed loop operation can cause the vehicle to run open loop and therefore become
a ‘quick fix’ solution.39
8. FUEL CONSUMPTION
The energy content of commercial petrol is 33 percent greater than that of
commercially available LPG. This means an LPG fuelled vehicle uses a third more
fuel to achieve the same power per kilometre than it would on petrol.
A 1974 estimate (BTCE, 1974) claimed that fuel consumption for an LPG vehicle
was ten percent greater than for the same vehicle on petrol. The latest Fuel
Consumption Guide (DPIE 1995/96) however, claims an EF Falcon operating on
LPG consumes 28 percent more than it would operating on petrol. This difference is
possibly due to the recent improvements in fuel efficiency for petrol engines (BTCE,
1994).
The fuel consumption values of vehicles in each category are illustrated in Figure 8-
1. The effect of tuning is also shown by referencing the Pre and Post-tune mean
values.
15
17
19
21
23
25
27
29
FUEL CONSUMPTION (L/100km)
TAXIS (Pre & Post) PRIVATE (Pre & Post) FLEET (Pre & Post)
denotes Mean Value
Figure 8-1: Fuel Consumption for Vehicle Categories
Pre-tune and Post-tune shown.
Key Findings:
· Fuel consumption levels are highly variable and vehicle specific.
· Private vehicles had the highest average (20.4 L/100km) then taxis (18.0
L/100km) and fleet vehicles (17.8 L/100km).
· Tuning improved fuel consumption across all categories by an average of
twelve percent. This, with the acknowledgment that taxis and fleet vehicles
may be better maintained than private vehicles, suggests that savings can be
made by tuning your vehicle.40
8.1 LPG FUEL CONSUMPTION COMPARED TO PETROL
In order to compare LPG results to the petrol results in the NISE Study, the energy
contents of LPG and petrol were standardised by converting the LPG results into a
petrol-equivalent. By dividing the fuel consumption values for LPG by the energy
equivalent ratio of LPG to petrol, a petrol-equivalent value for LPG was calculated.
This effectively eliminates the difference in energy content of the two fuels enabling a
direct comparison to be made.
0
2
4
6
8
10
12
14
16
18
20
L / 100 km
LPG
Pre- PostPETROL
Pre- Post- Pre- PostLPG (Petrol Equivalent)
Figure 8-2: LPG Fuel Consumption compared to Petrol
Key Findings:
· Tuning has a greater effect on fuel consumption (twelve percent improvement)
for LPG vehicles than for the same make and model petrol vehicles (two to
three percent improvement).
· In volumetric terms, the LPG sample fleet used 36 percent more fuel (than the
similar NISE fleet) for the pre-tune results and 33 percent for the post-tune.41
9. EFFECTIVENESS OF INSPECTION/MAINTENANCE SHORT TESTS
There is currently a great deal of interest in the development of a short emission test
for use in inspection and maintenance (I/M) programs. One of the objectives of the
NISE study was to evaluate and correlate the emission results from ADR27 and
ADR37 tests with emission results produced from a number of short emission tests.
This correlation has also been performed for LPG vehicles in this study.
A short emissions test should have the following characteristics:
· good correlation with ADR test results
· ability to identify high emitting vehicles whose criteria emissions (CO, HC and
NOx) may be reduced through tuning
· take only a few minutes to perform
· preferably be capable of being conducted at either a centralised, distributed or
roadside locations.
Until recently, the only short tests commonly in use were the Idle or High Idle tests.
The Idle test is performed without the engine loaded while CO and HC tailpipe
emissions are measured. The High Idle test is carried out the same way, but at a
more elevated engine speed (approximately 2500 rpm). However, there are a
number of shortcomings of both these tests. Some modern vehicles are known to
operate in an open loop mode whilst idling and switch to closed loop when the
vehicle is driven under load. In these instances, the idle tests would give little
indication of the vehicles’ overall emissions performance.
Also, as NOx is primarily produced when the engine is under load, an idle test will
not determine the emission level. Therefore, alternative measures such as a loaded
mode test and/or a functional/visual inspection of emissions control equipment are
required.
To address these issues, several short dynamometer (loaded) tests have been
developed in recent years. All vehicles in the LPG study were tested using the same
short tests (loaded and unloaded) used in the NISE study before and after tuning.
The tests are listed below. For details of the specific conditions to which the vehicles
were subject during testing, refer to Attachment 3.
Loaded Tests
· IM-240 (240 second transient cycle)
· SS-60 (Steady State)
· ASM-25/25 (Acceleration Simulation Mode)
Unloaded Tests
· Low Speed Idle (approximately 800 rpm)
· High Speed Idle (approximately 2500 rpm)42
9.1 IM-240 TEST RESULTS
The IM-240 is the test prescribed by the US EPA for enhanced vehicle inspection
and maintenance programs. The test involves a short (240 second) driving cycle
which is the same as the start of the ADR37 drive cycle, covering the first two
kilometres of the twelve kilometre test. Results are recorded in grams per kilometre
for HC, CO and NOx.
y = 0.772x - 0.992
R
2
 = 0.919
0
10
20
30
40
50
60
70
80
0 10 20 30 40 50 60 70 80 90 100
ADR CO Emissions (g/km)
IM 240 CO Emissions (g/km)
y = 0.474x + 0.134
R
2
 = 0.667
0.0
0.5
1.0
1.5
2.0
0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0
ADR HC Emissions (g/km)
IM-240 HC Emissions (g/km)
y = 1.249x - 0.203
R
2
 = 0.920
0.0
1.0
2.0
3.0
4.0
5.0
6.0
0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0
ADR NOx Emissions (g/km)
IM 240 NOx Emissions (g/km)
Figure 9-1: IM-240 vs ADR Test Results
Key Finding:
· As expected, the correlations for CO and NOx are very good, but surprisingly, it
was relatively low for HC.
The NISE study found this test to correlate the best with ADR37 and therefore the
most capable of identifying “gross emitters” in an inspection maintenance program.43
9.2 SS-60 TEST RESULTS
During the SS60, vehicles are driven on a chassis dynamometer at a constant 60
km/h. Exhaust emissions of CO, HC and NOx are analysed over the measurement
stage of the test and recorded in grams per minute.
Figure 9-2 illustrates the correlation of this test with the ADR37 emission test.
y = 0.467x - 1.820
R
2
 = 0.885
0
10
20
30
40
50
0 10 20 30 40 50 60 70 80 90 100
ADR CO Emissions (g/km)
SS60 CO Emissions (g/min)
y = 0.311x + 0.010
R
2
 = 0.759
0.0
0.2
0.4
0.6
0.8
1.0
1.2
1.4
0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0
ADR HC Emissions (g/km)
SS60 HC Emissions (g/min)
y = 0.319x + 0.290
R
2
 = 0.235
0.0
0.5
1.0
1.5
2.0
2.5
0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0
ADR NOx Emissions (g/km)
SS60 NOx Emissions (g/min)
Figure 9-2: SS-60 vs ADR Test Results
Key Finding:
· There is a reasonable correlation for CO and HC but a poor correlation for NOx 44
9.3 ASM-25/25 TEST RESULTS
The ASM25/25 test requires vehicles to be driven on a chassis dynamometer at a
speed of 40 km/h (or 25 mph as the name suggests) at 25 percent of the vehicle’s
maximum power. Manual vehicles are operated in second gear. Exhaust emissions
are measured raw (not diluted with air) using infra-red analysers. The results are
recorded in parts per million for HC and NOx and percent volume for CO.
y = 0.055x - 0.268
R
2
 = 0.891
0
1
2
3
4
5
6
0 10 20 30 40 50 60 70 80 90 100
ADR CO Emissions (g/km)
ASM CO Emissions (%/vol)
y = 45.233x + 38.545
R
2
 = 0.440
0
50
100
150
200
250
0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0
ADR HC Emissions (g/km)
ASM HC Emissions (ppm)
y = 733.179x - 8.774
R
2
 = 0.643
0
500
1000
1500
2000
2500
3000
3500
0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0
ADR HC Emissions (g/km)
ASM NO Emissions (ppm)
Figure 9-3: ASM-25/25 vs ADR Test Results
Key Finding
· There is a reasonable correlation for CO while HC and NOx correlate poorly.
9.4 IDLE TEST RESULTS
This is a static test whereby the vehicle remains stationary and the engine is
operated at an idle speed of ~800 rpm. The concentrations of raw exhaust emissions
are measured using infra-red analysers and results recorded in parts per million for
HC and percent volume for CO.  NOx is not measured as the engine is not placed
under load.45
y = 0.072x + 0.087
R
2
 = 0.706
0
1
2
3
4
5
6
7
8
0 10 20 30 40 50 60 70 80 90 100
ADR CO Emissions (g/km)
Idle CO Emissions (%/vol)
y = 92.072x + 43.015
R
2
 = 0.431
0
100
200
300
400
500
0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0
ADR HC Emissions (g/km)
Idle HC Emissions (ppm)
Figure 9-4: Idle vs ADR Test Results
Key Finding:
· There is a poor correlation of both pollutants.
9.5 HIGH IDLE TEST RESULTS
This is a static test whereby the vehicle remains stationary and the engine is
operated at a speed of 2500 rpm. The concentrations of the raw exhaust emissions
are measured using infra-red analysers and results recorded in parts per million for
HC and percent volume for CO. NOx is not measured as the engine is not placed
under load.46
y = 0.068x - 0.170
R
2
 = 0.710
0
1
2
3
4
5
6
7
0 10 20 30 40 50 60 70 80 90 100
ADR CO Emissions (g/km)
High Idle CO Emissions
(%/vol)
y = 64.329x + 4.789
R
2
 = 0.286
0
50
100
150
200
250
300
350
400
450
0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0
ADR HC Emissions (g/km)
High Idle HC Emissions
(ppm)
Figure 9-5: High Idle vs ADR Test Results
Key Finding:
· There is a poor correlation for both CO and HC.
9.6 SUMMARY OF SHORT EMISSION TEST CORRELATION RESULTS
Table 13 lists the “r” and “R2"
 values calculated for the LPG vehicles and the “r”
values reported by the NISE study.
The correlation values are deceptively high due to the fact that the low-emitting
vehicles can be detected quite accurately. The difficulty arises when the emission
levels are higher. As the emission levels increase, the ability of the short emission
tests to predict the actual emission level become more evident.47
Table 13: Relationship between ADR and Short Emission Tests
NISE LPG Study
r r R
2
SS 60 CO 0.84 0.94 0.89
HC 0.80 0.87 0.76
NOx 0.72 0.49 0.24
IM 240 CO 0.90 0.96 0.92
HC 0.94 0.82 0.67
NOx 0.90 0.96 0.92
ASM 25/25 CO 0.78 0.94 0.89
HC 0.64 0.66 0.44
NOx 0.68 0.80 0.64
High Idle CO 0.62 0.84 0.71
HC 0.70 0.54 0.29
NOx - - -
Idle CO 0.67 0.84 0.71
HC 0.72 0.66 0.43
NOx - - -
As was the case with petrol vehicles tested in the NISE Study, the IM-240 test
correlates best with the ADR test and would be the most effective test for predicting
vehicles with high emissions.
The SS60 and ASM loaded tests show better correlation for all three criteria
pollutants than the Idle and High Idle tests.48
10. SUMMARY OF RESULTS AND OBSERVATIONS
The results of the study have been presented primarily on a per vehicle basis due to
the small sample tested and the variation in results from vehicle to vehicle. However,
definite trends are evident from which the following observations have been made.
They are not conclusive but provide an indication of the characteristics of the LPG inservice fleet.
1. In comparison to petrol vehicles of similar make and model tested in the NISE
study, the exhaust emissions from the ADR27 LPG vehicles tested were
slightly lower than comparable petrol vehicles. The ADR37/00 LPG vehicles
also emitted less HC emissions, but their CO and NOx emissions were slightly
higher.
2. Of the three categories, the private vehicles (ADR27 and ADR37/00) were the
worst polluters. This may be due to the lower level of maintenance these
vehicles receive in comparison to fleet and taxis.
3. In general, LPG vehicles produce exhaust emissions that satisfy the current
ADR37 requirements.
4. As with the petrol fleet, the LPG fleet is tainted with “gross emitters” whose
emission levels far exceed the ADR limits. These vehicles exist in all three
categories.
5. Evaporative emissions from LPG vehicles far exceed the ADR limits. This was
also found to be the case with the petrol engined vehicles tested in the NISE
Study. The result is a significant concern for both the petrol and LPG vehicle
fleets.
6. In general, emissions of CO and HC from the LPG in-service fleet were
reduced after tuning. However, NOx emissions remained unchanged, or in
some cases actually increased.
7. Tuning of open loop fuel management vehicles has a significant benefit on
reducing CO and HC emissions while slightly increasing NOx emissions.
However the effect of tuning on vehicles equipped with closed loop fuel
management systems was minimal. Tuning LPG open loop vehicles is a
sensitive operation that, if not performed with the correct and most advanced
equipment and by experienced personnel, leads to large variations in
emission levels. That is, introducing a small tuning change (ie a “tweak” of the
system) can result in a large increase or decrease in emissions.
8. Some vehicles were found to have a mix of components from different kit
manufacturers and in at least one case this had an adverse effect on
emissions.
9. Fuel consumption can be improved by twelve percent (on average) by tuning.49
10. Correlation of Inspection & Maintenance short tests with the ADR test for LPG
vehicles is similar to that of the petrol vehicles. That is, the IM240 test has the
best correlation followed by the other loaded tests, SS60 and ASM25/25 . The
two idle tests had the lowest correlation.
The study also identified deficiencies in the data available on the make up and
operation of the LPG fleet, which limit the capacity to use the results from this study
to accurately estimate LPG vehicle impacts on urban air quality.50
10. REFERENCES
ABS, 1995, Motor Vehicle Census Australia, Australian Bureau of Statistics,
Australian Government Publishing Service, 1995.
ALPGA, 1993, Exhaust Emissions From LP Gas Fuelled Vehicles 1993 - The
Complete Picture, Australian Liquefied Petroleum Gas Association Ltd.
Borgas, L. 1993, ‘LPG Motor Fuels’, paper presented to SAE Australasia conference
Motor Vehicles and the Environment, Melbourne, April 1993.
BTCE, 1974, Liquefied Petroleum Gas as a Motor Vehicle Fuel, BTE Report no. 11,
AGPS, Canberra.
BTCE, 1994, Alternative Fuels in Australian Transport, Bureau of Transport and
Communications Economics, Canberra.
DMAQC, 1987, Vehicle Fleet Survey: Opportunities for reducing Air Pollution through
the use of Compressed Natural Gas and Propane, Denver Metropolitan Air
Quality Council, October 1987.
DPIE, 1995/96, Fuel Consumption Guide, Department of Primary Industries and
Energy, Australian Government Publishing Service, Canberra.
FORS, 1996, Motor Vehicle Pollution in Australia - A Report on the National InService Vehicle Emissions Study, Australian Government Publishing Service,
May 1996.
NSW EPA, 1996, Determination of an LPG Certification Test Fuel, 1996.
US EPA, 1995, Analysis of the Economic and Environmental Impacts of LPG as a
vehicle fuel, Office of Mobile Sources, Ann Arbor, Michigan, April 1985.
10.1 INFORMATION ON DEDICATED LPG FUELLED VEHICLES
Hollemans B., Conti L., de Kok P., ‘Propane the “Clean” Fuel for the next century for
light and heavy duty vehicles’, paper presented to 1995 Windsor Workshop on
Alternative Fuel, Toronto, Canada, June 1995.
US EPA, 1995, Analysis of the Economic and Environmental Impacts of LPG as a
vehicle fuel, Office of Mobile Sources, Ann Arbor, Michigan, April 19851LPG In-Service
Vehicle Emissions Study
ATTACHMENTS CONTENTS
ATTACHMENT
1. CONFIRMATION LETTER TO VEHICLE OWNER...............................................A-1
2. INSPECTION AND TEST SEQUENCE...................................................................A-3
3. TESTING SPECIFICATIONS..................................................................................A-7
APPENDIX 1: ASM2525 TEST ................................................................................... A-8
APPENDIX 2: SS60 TEST .......................................................................................... A-9
APPENDIX 3: IDLE TEST ......................................................................................... A-12
APPENDIX 4: HIGH IDLE TEST ................................................................................ A-13
APPENDIX 5: IM240 TEST ...................................................................................... A-14
APPENDIX 6: GENERAL REQUIREMENTS & COSTS .................................................... A-19
4. HANDOVER INSPECTION....................................................................................A-20
5. CLOSED LOOP VS OPEN LOOP ENGINE MANAGEMENT SYSTEMS............A-22Page A - 1
ATTACHMENT 1
· CONFIRMATION LETTER
DEAR CAR OWNER
As a follow-up to the recent telephone call from a representative of the Environment
Protection Authority of ___, I am writing to confirm details about the testing program for
LPG-fuelled vehicles.
The EPA representative will have explained that your household was identified as owning an
LPG dual-fuelled motor vehicle when interviews were conducted for the national in-service
vehicle study, which is being managed by the Federal Office of Road Safety.
You may recall that the Federal Office of Road Safety has responsibility for a number of
environmental issues relating to motor vehicles and that the national in-service vehicle study
is being conducted to gather information about the relationships between motor vehicles and
the air quality of our cities.
The study, until recently, has focussed on the operation of petrol-engine passenger vehicles
only. However, it has been decided that there would be benefit in testing a small number of
LPG dual-fuelled vehicles because of the increased popularity as both private and
commercial transport. Testing of the LPG vehicles will provide useful information on the
quality of operation and general condition of these cars.
Should you agree to have your car tested, the following procedures will take place:
TESTING OF YOUR VEHICLE
Testing of your vehicles would be undertaken in a specially equipped laboratory under the
supervision of highly qualified engineers. No actual road testing is involved.
Although your car would be needed for approximately 3 days, the actual testing is quite short,
involving a pre-tune and then a post-tune test of some 2-3 hours. However, the preparation ,
conditioning, tuning and checking of the vehicle between the two tests is quite extensive and
accounts for most of the time we would have your car.
INSURANCE
Arrangements have been made through the NRMA, as well as the Commonwealth and the
Testing Station to have the insurance cover on all the vehicles involved in testing.
While a vehicle is with the laboratory, it is covered by that organisation’s insurance cover.
This cover extends to the collection and delivery of each participating vehicle.
The replacement vehicle is provided to participating householders over the testing period is
covered by a standard NRMA comprehensive insurance policy with the normal excess being
covered by the Commonwealth Government.
REPLACEMENT VEHICLE
A replacement current-model vehicle will be provided to you, for use during the time your Page A - 2
vehicle is being tested.
There are, of course, a few minor formalities to be dealt with at handover of vehicles. These
are standard requirements and we ask that you read the conditions prior to handover of your
vehicle and keep a signed copy for your own purposes.
It is essential that the driver of the replacement vehicle has a current driver’s licence.
HANDOVER DOCUMENT
The handover document contains an outline of the obligations of the driver whilst the
replacement vehicle is in his or her care. This includes such items as compliance with all road
laws, not driving whilst under the influence of alcohol or drugs, and an expectation that you
will look after the vehicle. Once again you should read this before signing.
CHECK LIST ON CONDITION OF YOUR VEHICLE
A check sheet on the condition of your vehicle is also to be filled out by the officer collecting
your vehicle and signed by you or your authorised agent at the time of collection and return
of your vehicle.
RETURN OF YOUR VEHICLE
Every effort is made to ensure that participating householders are not inconvenienced
throughout the test period and to make their contribution to the study worthwhile.
The Federal Office of Road Safety does this by providing vehicle with a tune-up, and in
addition the car will be cleaned and filled with LPG before it leaves the testing station. The
tune-up will be done by a licensed LPG service agent who is a member of the Australian
Liquefied Petroleum Gas Association.
On the return of your vehicle, you will be provided with a report summarising the test results.
If, for some reason, your vehicle does not fully meet normal roadworthy requirements, you
will be notified of what needs to be rectified. This is purely advisory and no action will be
taken against any owner.
I hope you find this extension to the national in-service vehicle study interesting and can
contribute to its success. Thank you for taking the time to read this letter.
A representative of the EPA Motor Vehicle Testing Laboratory will contact you again shortly
to talk about your participation in the testing program. In the meantime, if you have any
questions at all about the testing, please contact _______ from the EPA.
Telephone: ________
Yours sincerely
Peter Anyon
Project Director
August 1995Page A - 3
ATTACHMENT 2
INSPECTION AND TEST SEQUENCE
Part 1  Pre-Test Inspection
The laboratory representative at the time  of vehicle pick up shall be required to
complete an inspection sheet prior to accepting a test vehicle.  The inspection sheet is
to be signed by the laboratory representative and the vehicle owner (or person
handing over the test vehicle).
Once accepted, the owner will be given a replacement vehicle (except in the case of
taxis where no replacement vehicle will be given) and the relevant paperwork for
insurance purposes shall be completed.
The test vehicle will be driven to the predetermined licensed LPG  service centre.
The following activities will be performed by approved staff:
· Fill the vehicles integral LPG cylinder with commercial LPG.
· Inspect the general condition of  the engine and identify any problems and
parts that are required when tuning the  vehicle; particular attention paid to
the LPG system components.
· Record vehicle details as per the FORS pre inspection check sheet, noting
additional features and component details specific to the LPG system.  Such
additional features should include the following:
- LPG converter make:
1.   AIROD
2.   BRC
3.   CENTURY
4.   GRFT
5.   IMPCO
6.   LANDI
7.   LANDI HARTOG
8.   LANDI RENZO
9.   O.H.G.
10. O.M.V.L.
11. OMNIGAS
12. POLIAUTO
13. VIALLE
- control system:
1. CLOSED LOOP
2. OPEN LOOP
- conversion kit type: Page A - 4
1. FIXED VENTURI FLOWPage A - 5
2. VARIABLE VENTURI FLOW
3. IMPCO/O.H.G. CARBURETTOR
- LPG conversion kit compatibility:
1. YES
2. NO
- general condition of lines and other accessories.
These LPG conversion kit features shall be entered into their designated fields and if additional
fields are required to enter any other features deemed necessary then the Modifications field in
the FORS database shall be utilised.
· Make provision in the LPG supply line for a LPG compatible hose to be connected,
for bypassing the vehicles integral LPG tank when undertaking emission testing in the
testing laboratory.  The line shall be connected to an LPG external test tank at the
testing laboratory prior to testing the vehicle.
The pre-test checklist used for the test vehicles during the FORS Study shall be
completed before testing is commenced.  This checklist shall entail items (e.g., the
features listed above) that are relevant to LPG systems.
Part 2 Preparing Vehicle for Testing
All vehicles shall be prepared in the following manner when undertaking exhaust
emission tests:
· drain fuel in petrol tank,
· fill 40% of petrol tank capacity with FORS specification test fuel,  and weigh
the vehicle to determine its inertia category without the external LPG cylinder
fitted,
NOTE: If evaporative emission test ( SHED ) is to be carried out; replenish
petrol tank with the  FORS specified fuel  and ensure that the LPG
test blend cylinder is in the boot of the vehicle during the
evaporative emission test.
· connect LPG external cylinder containing the specified LPG test blend to
flexible supply line, bypassing the vehicles’ integral tank, and ensuring that
the LPG external cylinder remains in the boot of the vehicle during the entire
duration of preconditioning and testing,
· complete the normal ADR 37 preconditioning cycle, and
· allow a soaking period of at least 12 hours before commencement of testing.
Any work requiring the replacement of parts and tuning is to be completed by the
tuning contractor after completion of the first [pre-tune] round of tests.  Apart from
any adjustments to enable safe operation of the vehicle during the test, the person Page A - 6
undertaking the re-test inspection shall not undertake any work to alter the “as
received” condition of the vehicle, as this would defeat the objective of the pre-tune
test program.
PART 3 Testing Program
The sequence of the testing program is as follows.
1. Inspect vehicle and as received.
* If suitable for testing, go on to item 2 and provide report on pre-test
inspection, including advice of parts required for tuning, and other
matters requiring attention by the LPG servicing contractor.
* If not suitable for testing, vehicle should be tuned, cleaned [washed
externally and vacuumed & wiped over inside], filled with LPG, and
returned to vehicle owner with a copy of the completed checklist
[including tuning information].
2. Prepare and precondition vehicle in accordance with ADR37/00 ensuring
LPG external cylinder is in the boot of the vehicle, including requirements for
evaporative emissions test, where applicable and the instructions specified in
Attachment 3a.
3. Overnight temperature soak as specified in ADR37/00.
4. Commence ADR37/00 test sequence.
5. At completion of heat build [where required] conduct Fuel Filler Cap Sealing
test and Canister sniff check.
6. Complete ADR37/00 drive cycle ADR37/00 ensuring LPG external cylinder is
outside the vehicle.
7A. For vehicles undergoing ADR37/00 Evaporative Emissions test, complete test
in accordance with ADR37/00 procedures and then return vehicle to
dynamometer. Immediately prior to commencing the Acceleration Simulation
Mode [ASM] Test at Step 8, bring vehicle to normal operating temperature by
running vehicle at the ASM speed and load for 5 minutes.
7B. For vehicles not undergoing ADR37/00 Evaporative Emissions test, leave
vehicle on the dynamometer. If the vehicle does not immediately proceed to
the Acceleration Simulation Mode [ASM] Test at Step 8, bring vehicle to
normal operating temperature by running vehicle at the ASM speed and load
for 5 minutes immediately prior to commencing the ASM test.
8. Conduct Acceleration Simulation Mode test.
9. Conduct Steady State Loaded [60km/hr] test.Page A - 7
10. Conduct Steady State [High Idle] test and immediately the test is completed
conduct the Catalyst Temperature test.
11. Conduct the Steady State [Idle] test.
12. Conduct the IM240 test.
13. Provide vehicle to licensed LPG servicing contractor for tune/repair to
optimise operation on LPG and replacement of parts.
14. Repeat steps 2 to 12 of the above sequence.
15. Prepare summary sheet for vehicle owner.
16. Process test result data required for analysis and reporting.
17. Testing completed - vehicle cleaned inside and out.
18. Vehicle driven to LPG servicing contractor for removal of the bypass line and
return of the vehicle to its standard condition.
19. Return vehicle to owner in accordance with contract requirements.Page A - 8
ATTACHMENT 3
TESTING SPECIFICATIONS
The LPG test fuel shall be contained within certified LPG cylinders.  Utmost care should be taken to ensure
safety whilst handling the LPG cylinders.
The following tests shall be undertaken in accordance with the specified procedures:
NAME OF TEST TEST PROCEDURE
EMISSIONS TESTS
ADR37/00 EXHAUST
EMISSIONS
ADR37/00 EVAPORATIVE
EMISSIONS
ACCELERATION
SIMULATION MODE
[ASM2525]
STEADY STATE LOADED
[60km/hr]
STEADY STATE [IDLE]
STEADY STATE [HIGH IDLE]
IM240
As set out in Clauses 37.6 to 37.8 of Australian Design Rule [ADR] 37/00 Emission
Control for Light Vehicles, subject to the following conditions:
[1] Where the vehicle is not going to be subject to the ADR37/00 evaporative
emissions test, the heat build and associated drain and fill of the petrol
tank shall not be conducted.
[2] The vehicle shall be weighed in its "as delivered" condition, and the road
power absorber setting shall be the appropriate value from Table 8.2 of
ADR37/00.
[3] If the vehicle is fitted with air conditioning, the road power absorber
setting shall be increased by 10% and the air conditioning unit switched
off.
[4] The ADR37/00 default speeds shall be used to determine manual gear
change points.
[5] The actual distance recorded in the test shall be used to calculate
emissions in g/km.
[6] The HC and fuel consumption calculations will be different to those used
for petrol. Therefore, the equations illustrated in section 1.7 of Appendix
5 [IM240] shall be used.
As set out in Clauses 37.6 to 37.7 of ADR37/00 Emission Control for Light
Vehicles, subject to the following condition:
[1] The attachment of a fuel temperature sensor to the outside surface of the
fuel tank is an acceptable alternative method to that specified in
ADR37/00, provided it can be established that this method provides
equivalent results to the method specified in the ADR.
As set out in Appendix 1 to this attachment.
As set out in Appendix 2 to this attachment.
As set out in Appendix 3 to this attachment.
As set out in Appendix 4 to this attachment.
As set out in Appendix 5 to this attachment.Page A - 9
ATTACHMENT 3
Appendix 1
Acceleration Simulation Mode Test Procedure [ASM2525]
The Acceleration Simulation Mode Test shall be conducted in accordance with the following
procedures:
1. The vehicle is placed  on the dynamometer and driven to the target speed of 40km/hr ±
1km/hr.
2. Vehicle load is determined by the formula
Equivalent Test Inertia Weight [lbs]
300
- where the horsepower is determined at 25mph [possible values range from 6-20hp at 25mph].
The load applied simulates 25% of the power required to accelerate the vehicle at
3.3mph/second at 25mph.
The load applied to the dynamometer at 40km/hr shall be determined from the
“Determination of Load” table used in the FORS test procedure. Flywheels, electrical devices
or other means of simulating Equivalent Test Inertia Weight [mass] shall be used.
3. Maintain test condition for 1 minute.
4. For vehicles with manual transmissions, the vehicle is tested in 2nd gear, for automatics in
Drive.
5. The exhaust emissions are collected after a minimum of 10 seconds of operation in the speed
window. If the emission readings are stable the test is completed and readings recorded. If the
readings are unstable [±20ppm HC, ±0.20% CO, ±150ppm NOx] continue  the test for 60
seconds and collect the sample within the last 10 seconds and record the result.
6. The raw exhaust measurements of HC [in ppm] and CO [in %vol] shall be recorded using a
calibrated non-dispersive infrared analyser at least equivalent to a  BAR90 3-gas smart bench.
The raw exhaust measurements of NOx [recorded as NO in ppm] shall be recorded using a
calibrated Horiba VIA 300 non-dispersive infra red analyser or equivalent.Page A - 10
ATTACHMENT 3
Appendix 2
Steady State Loaded [60km/Hr] Test Procedure
Method Of Measurement Of The Rates Of Emission Of Carbon Monoxide, Hydrocarbons And
Oxides Of Nitrogen In The Exhaust Gases Of A Motor Vehicle Operating At A Steady Speed Of
60 Km/Hr By The Method Of Constant Volume Sampling
1. The Test
The test consists of driving the vehicle on a chassis dynamometer with the aid of a driving schedule
indicator so that the vehicle speed, measured from the dynamometer rolls, is at a constant speed of
60 km/hr.
The test is to consist of 2 phases:
(a)    a preconditioning phase of 5 minutes at 60 km/hr, and
(b)    a measurement phase.
The exhaust emissions must be diluted with air to a constant volume. A portion of the diluted mixture
must be sampled continuously during the measurement phase of the test and collected in a  bag for
analysis. A parallel sample of the dilution air must also be collected during this phase for analysis.
The concentrations of carbon dioxide, carbon monoxide, and oxides of nitrogen in the samples
collected are determined as normal petrol.  However, hydrocarbon emissions will be calculated by
considering the ratio of propane to butane in the LPG blend and the respective HC fraction and HC
density as illustrated in the following equation:
HC
V HC
D
mix
mix HC conc
=
´ ´ ´
-
r 10
6
where Vmix
 (L) = volume of the mixture, equation of which will remain the same for LPG.
HCconc
 (mol p.p.m. carbon equivalent) = concentration of HC from emissions analysis.
D (km) = measured driven distance.
density of HC for propane = 0.6110 g/L and density of HC for butane = 0.6040 g/L
then density of HC for LPG test blend of 60/40, rHC = 0.6082 g/L.
Raw exhaust measurements shall also be recorded as per the latest testing schedule of the FORS
Study that was agreed by the testing authorities and laboratories.
2. Test Conditions
The test must be carried out under the following conditions:
(a) The test vehicle must be preconditioned as described above.
(b) The vehicle must be tested at an ambient air temperature between 20°C and 30°C.
(c) The deviation in speed at any given time during the measurement phase must not exceed 1
km/hr.
(d) The road load power setting shall be determined by reference to the vehicle's engine capacity
and dynamometer inertia setting as specified in the table below. If the vehicle is equipped
with air conditioning, the air conditioner must be switched off during the test.Page A - 11
Table - Calculation of Dynamometer Road Load Setting
Engine Capacity of Test
Vehicle [L]
Inertia Setting [kg] Road Load Power [kW]
< 1.7 794 5.7
> 1.7  &  < 2.9 1134 7.0
> 2.9 1474 8.0
(e) An auxiliary fan with a capacity of not more than 2.5 cubic metres per second must be used to
cool the engine.
(f) Prior to the test the air pressure in the tyres on the drive wheels of the vehicle must be equal
to or greater than the pressure recommended, if any, in the owner's manual and, in any case,
must be less than 310 kilopascals.
(g) The constant volume sampling unit must be connected to the vehicle exhaust pipe or pipes
and turned on, the cooling fan must be turned on and the engine compartment cover must be
raised before the beginning of the test.
The measurement phase of the test and the collection of samples are to begin after the
preconditioning phase has ended. The engine ignition must not be turned off at the end of the
measurement phase.
(h) The engine must be started according to the procedures recommended, if any, in the owner's
manual.  If the engine fails to start, the starting procedure must be repeated. A vehicle
equipped with an automatic choke must be operated according to the procedures
recommended, if any, in the owner's manual.  If no recommendation is made as to the time at
which the accelerator pedal is to be depressed in order to return the engine to normal idle
speed, that time must be 13 seconds after the engine starts.  A vehicle equipped with a manual
choke must be operated according to the procedures recommended, if any, in the owner's
manual. If no recommendation is made as to manual choke operation, the choke must be
operated to maintain engine idle speed between 1050 and 1150 rpm during the first 20
seconds of the preconditioning phase and used during the remainder of the phase if
considered necessary by the person performing the test to keep the engine running.
(i) If the owner's manual does not recommend a procedure for starting a warm engine, the engine
(whether equipped with automatic or manual choke) can be started by depressing the
accelerator pedal through about half of the available distance and cranking the engine until it
starts.
(j) The following driving requirements must be met during the test -
(i) The transmission must be placed in the gear recommended in the owners manual for
the speed of 60 km/hr.
(ii) A vehicle equipped with a freewheeling or overdrive unit must be tested with the
freewheeling or overdrive unit placed out of operation.
3. Exhaust Collection and Sampling
A connecting tube must be used to connect the vehicle exhaust pipe or pipes to a constant volume
sampling unit, which must dilute the exhaust gases to a constant volume of diluted  mixture with
dilution air which has been drawn through a charcoal filter. The filter assembly must be sized and
maintained so that the pressure in the area where the exhaust gases mix with dilution air is less than
0.25 kilopascals below ambient air pressure when the constant volume sampling unit is in operation.Page A - 12
If the sampling unit employs a positive displacement pump, the temperature of the diluted mixture
immediately before it enters the pump must not vary by more than 12°C during the test.
The sampling unit must have a capacity of not less than 0.09 cubic metres per second. The total
volume of diluted gases, corrected to 20°C and 101.325 kilopascals, passed through the sampling unit
during each phase of the test must be measured.
A constant proportion of the flow of diluted exhaust gases must be sampled at a rate of not less than
0.08 litres per second and collected in a separate collection bag for the measurement phase of the test.
Dilution air must be sampled at a constant flow rate and similarly collected during the test.
4. Analysis
Within 10 minutes of the conclusion of the measurement phase of the test, the concentration of
hydrocarbons, expressed as propane, in the samples of diluted exhaust gases and dilution air collected
during that phase must be determined using flame ionisation detector analysis, the concentrations of
carbon monoxide and carbon dioxide in the samples must be determined using non-dispersive infrared
analysis and the concentration of oxides of nitrogen in the samples must be  determined using
chemiluminescent analysis.
The hydrocarbon analyser must be fuelled with a mixture of between 38% and 42% by volume
hydrogen, with the balance being helium. The hydrocarbon analyser must be zeroed with air and the
carbon monoxide, carbon  dioxide and oxides of nitrogen analysers must be zeroed with either air or
nitrogen. The concentration of impurities in the zero gas or gases must not exceed 6 ppm.
hydrocarbons (expressed as propane), 10 ppm. carbon monoxide and 1 ppm. nitric oxide. For the
purposes of this analysis air includes a blend made of nitrogen and oxygen with the oxygen
concentration between 18% and 21% by volume. The hydrocarbon analyser must be spanned with a
propane and air mixture which will result in a response equivalent to  not less than 70% of the full
scale deflection. The carbon monoxide analyser must be spanned with a carbon monoxide and
nitrogen mixture which will result in a response equivalent to not less than 70% of the full scale
deflection. The carbon dioxide analyser must be spanned with a carbon dioxide and nitrogen mixture
which will result in a response equivalent to not less than 70% of the full scale deflection. The oxides
of nitrogen analyser must be spanned with a nitric oxide and nitrogen mixture which will result in a
response equivalent to not less than 70% of the full scale deflection. At least 3 gas mixtures must be
used to calibrate each of the analysers.Page A - 13
ATTACHMENT 3
Appendix 3
Steady State [Idle] Test Procedure
The Steady State [Idle] Test shall be conducted in accordance with the following procedures:
1. Immediately before the test, the engine must be brought to normal operating temperature.
2. The engine is started and kept running throughout the test, with the accelerator pedal not
depressed.
3. For vehicles with manual transmissions, the vehicle shall be in neutral gear with the clutch
engaged. For vehicles with automatic or semi-automatic transmissions, the gear selector shall
be in the Drive position and the handbrake placed in the fully "on" position.
4. For vehicles equipped with a manual choke, the choke must be in the "off" position.
5. The inlet probe of the sampling probe of a calibrated
4
 non-dispersive infrared analyser shall
be positioned in the exhaust pipe at any point between 350  mm and 500 mm from the
discharge end of the exhaust pipe. For the purposes of the test, the pipe may be extended by
use of an extension piece connected to the vehicle's discharge outlet with a suitable
connection which does not allow dilution of the exhaust gases by air. Where the vehicle is
fitted with more than one exhaust pipe, the concentration shall be measured in each pipe.
6. The raw exhaust measurement shall be recorded as the maximum value of the concentration
of CO [in %vol] and total HC [in ppm] as determined by the analyser over a period of
between 30 and 60 seconds, beginning not earlier that 60 seconds after the probe has been
inserted in the exhaust pipe. Where the vehicle is fitted with more than one exhaust pipe, the
maximum value shall be the highest value from either pipe.
                                                           
4
The analyser shall be calibrated within the preceding 30 days by being zeroed with dry nitrogen which contains less than 10ppm CO, or 6ppm total HC
[equivalent carbon response], as applicable, and spanned with a CO or total HC mixture, as applicable, which will result in a response equivalent to not less
than 70% of the full scale deflection. The instrument must be zeroed and spanned using a secondary electronic of mechanical system prior to each
measurement.Page A - 14
ATTACHMENT 3
Appendix 4
Steady State [High Idle] Test Procedure
The Steady State [High Idle] Test shall be conducted in accordance with the following procedures:
1. Immediately before the test, the engine must be brought to normal operating temperature.
2. The engine is started and kept running throughout the test, with the accelerator pedal
depressed until the engine rotational speed has stabilised at 2500 rpm ±50rpm.
3. For vehicles with manual transmissions, the  vehicle shall be in neutral gear with the clutch
engaged. For vehicles with automatic or semi-automatic transmissions, the gear selector shall
be in the neutral position and the handbrake placed in the fully "on" position.
4. For vehicles equipped with a manual choke, the choke must be in the "off" position.
5. The inlet probe of the sampling probe of a calibrated
5
 non-dispersive infrared analyser shall
be positioned in the exhaust pipe at any point between 350 mm and 500 mm from the
discharge end of the exhaust pipe. For the purposes of the test, the pipe may be extended by
use of an extension piece connected to the vehicle's discharge outlet with a suitable
connection which does not allow dilution of the exhaust gases by air. Where the vehicle is
fitted with more than one exhaust pipe, the concentration shall be measured in each pipe.
6. The raw exhaust measurement shall be recorded as the maximum value of the concentration
of CO [in %vol] and total HC [in ppm] as determined by the analyser over a period of
between 30 and 60 seconds, beginning not earlier that 60 seconds after the sampling has
commenced and the engine speed has stabilised. Where the vehicle is fitted with more than
one exhaust pipe, the maximum value shall be the highest value from either pipe.
                                                           
5
The analyser shall be calibrated within the preceding 30 days by being zeroed with dry nitrogen which contains less than 10ppm CO, or 6ppm total HC
[equivalent carbon response], as applicable, and spanned with a CO or total HC mixture, as applicable, which will result in a response equivalent to not less
than 70% of the full scale deflection. The instrument must be zeroed and spanned using a secondary electronic of mechanical system prior to each
measurement.Page A - 15
ATTACHMENT 3
Appendix 5
Modified IM240 Test Procedure
1. IM240 TEST PROCEDURE
1.1 General Requirements
1.1.1 Ambient Conditions
The ambient temperature, absolute humidity, and barometric pressure shall be recorded
continuously during the transient driving cycle or as a single set of readings up to 4 minutes
before the start of the transient driving cycle.
1.1.2 Restart
If shut off, the vehicle shall be restarted as soon as possible before the test and shall be
running at least 30 seconds prior to the transient driving cycle.
1.2 Pre-inspection and Preparation
1.2.1 Accessories
All accessories (air conditioning, heat, demisters, radio, automatic traction control if
switchable, etc.) shall be turned off.
1.2.2 Leaks
The vehicle shall be inspected for exhaust leaks. Audio assessment while blocking exhaust
flow or gas measurement of C0
2
 or other gases shall be acceptable. Vehicles with leaking
exhaust systems shall be rejected from testing.
1.2.3 Operating Temperature
The vehicle temperature gauge, if equipped and operating, shall be checked to assess
temperature. Vehicles in overheated condition shall be rejected from testing.
1.2.4 Tyre Condition
Vehicles shall be rejected from testing if the tyre cords are visible. Vehicle  tyres shall be
visually checked for adequate pressure level. Drive wheel tyres that appear low shall be
inflated to approximately 30 psi, or to tyre sidewall pressure, or the manufacturer's
recommendation.
1.2.5 Ambient Background
Background concentrations of HC, CO, NOx, and C0
2
 shall be sampled as specified in
ADR37/00 to determine background concentration of CVS dilution air. The sample shall be
taken for a minimum of 15 seconds within 120 seconds of the start of the transient driving
cycle, using the same analysers used to measure tailpipe emissions. Average readings over
the 15 seconds for each gas shall be recorded in the test record. Testing shall be prevented
until the average ambient background levels are less than 20 ppm HC, 30 ppm CO, and 2
ppm NOx or outside ambient air levels, whichever are greater.
1.2.6 Sample System Purge
While a lane is in operation, the CVS shall continuously purge the CVS hose between tests,
and the sample system shall be continuously purged when not taking measurements.Page A - 16
1.2.7 Negative Values
Negative gram per second readings shall be integrated as zero and recorded as such.Page A - 17
1.3 Equipment Positioning and Settings
1.3.1 Roll Rotation
The Vehicle shall be manoeuvred onto the dynamometer with the drive wheels positioned
on the dynamometer rolls. Prior to test initiation, the rolls shall be rotated until the vehicle
laterally stabilises on the dynamometer. Drive wheel tyres shall be dried if necessary to
prevent slippage during the initial acceleration.
1.3.2 Cooling System
Testing shall not  begin until the test cell cooling system is positioned and activated. The
cooling system shall be positioned to direct air to the vehicle cooling system, but shall not be
directed at the catalytic converter, where fitted.
1.3.3 Vehicle Restraint
Testing shall not begin until the vehicle is restrained. Any restraint system shall meet the
requirements of ADR37/00.
1.3.4 Dynamometer Settings
Dynamometer power absorption and inertia weight settings shall be those appropriate to
vehicle as specified in Table 1. If the vehicle is fitted with air conditioning, the road power
absorber setting shall be increased by 10% and the air conditioning unit switched off.
Table 1 - Determination of Dynamometer Settings
No. Of Cylinders Actual Road Load
[hp]
Test Inertia Weight
[lbs]
4 9.4 2500
5 10.3 3000
6 10.3 3000
8 11.2 3500
1.3.5 Exhaust Collection System
The exhaust collection system shall be positioned to ensure complete capture of the entire
exhaust stream from the tailpipe during the transient driving cycle. The system shall meet
the requirements of ADR37/00.
1.4 Vehicle Preconditioning
The vehicle shall be preconditioned by driving the vehicle on the dynamometer at 30 miles per
hour for up 90 seconds at road load.
1.5 Vehicle Emission Test Sequence
1.5.1 Transient Driving Cycle
The vehicle shall be driven over the IM240 drive cycle
1.5.2 Driving Trace
The inspector shall follow an electronic, visual depiction of the time/speed relationship of the
transient driving cycle (hereinafter, the trace). The visual depiction of the trace shall be of sufficient
magnification and adequate detail to allow accurate tracking by the driver and shall permit the driver
to anticipate upcoming speed changes. The trace shall also clearly indicate gear shifts as specified in Page A - 18
clause 2.5.3.
1.5.3 Shift Schedule
For vehicles with manual transmissions, the operator shall shift gears according to the shift schedule
used in the IM240 Test Procedures from the FORS Study. Gear shifts shall occur at the points in the
driving cycle where  the specified speeds are obtained. For vehicles with fewer than six forward gears
the same schedule shall be followed with shifts above the highest gear disregarded.
1.5.4 Speed Excursion Limits
Speed excursion limits shall apply as follows:
[a] The upper limit is 2 mph higher than the highest point on the trace within 1 second of the
given time.
[b] The lower limit is 2 mph lower than the lowest point on the trace within 1 second of the given
time.
[c] Speed variations greater than the tolerances are acceptable provided they occur for no more
than 2 seconds on any occasion.
[d] Speeds lower than those prescribed during accelerations are acceptable provided the vehicle is
operated at maximum available power during such accelerations until the vehicle speed is
within the excursion limits.
[e] Exceedences of the limits in [a] through [c] of this paragraph shall automatically result in a
void test. The test facility manager can override the automatic void of a test if the manager
determines that the conditions specified in paragraph [d] occurred. Tests shall be aborted if
the upper excursion limits are exceeded. Tests may be aborted if the lower limits arc
exceeded.
1.5.5 Speed Variation Limits
A linear regression of feedback value on reference value shall be performed on each transient driving
cycle for each speed using the method of least squares, with the best fit equation having the form:
y = mx + b,
where:
y = the feedback (actual) value of speed; m = the slope of the regression line; x = the
reference value; and
b =  the y-intercept of the regression line.
The standard error of estimate (SE) of y on x shall be calculated for each regression line. A transient
driving cycle that exceeds the following criteria shall be void and the test shall be repeated:
SE = 2.0 mph maximum;
m = 0.96-1.01;
r
2
 = 0.97 minimum; and
b = ± 2.0mph.
1.5.6 Distance Criteria
The actual distance travelled for the transient driving cycle and the equivalent vehicle speed (ie., roll
speed) shall be measured If the absolute difference between the measured distance and the theoretical
distance for the actual test exceeds 0.05 miles, the test shall be void.Page A - 19
1.5.7 Vehicle Stalls
Vehicle stalls during the test shall result in a void and a new test. More than 3 stalls shall result in test
failure.
1.5.8 Dynamometer Controller Check
For each test, the measured horsepower, and inertia if electric simulation is used, shall be integrated
from 55 seconds to 81 seconds (divided by 26 seconds), and compared with the theoretical road-load
horsepower (for the vehicle selected) integrated over the same portion of the cycle. The same
procedure shall be used to integrate the horsepower between l89 seconds to ~01 seconds (divided by
12 seconds). The theoretical horsepower shall be calculated based on the observed speed during the
integration interval. If the absolute difference between the theoretical horsepower and the measured
horsepower exceeds O.5 hp, the test shall be void. For vehicles over 8500 pounds GVWR, if the
absolute difference between the theoretical horsepower and the measured horsepower exceeds 2 hp,
the test shall be void.
The dynamometer controller check in this clause 1.5.8 is not required, provided the dynamometer is
checked at least daily as part of the laboratory normal quality assurance program.
1.5.9 Inertia Weight Selection
Operation of the inertia weight selected for the vehicle shall be verified as specified in ADR37/00. For
systems employing electrical inertia simulation, an algorithm identifying the actual inertia force
applied during the transient driving cycle shall be used to determine proper inertia simulation. For all
dynamometers, if the observed inertia is more than 1% different from the required inertia, the test
shall be void.
1.5.10 CVS Operation
T he CVS operation shall be verified throughout the test by monitoring the difference in pressure from
atmosphere for a CFV-typeCVS or the difference in pressure between upstream and throat pressure on
a SSV-type CVS. The minimum values shall be determined from system calibrations. Monitored
pressure differences below the minimum values shall void the test.
1.6  Emission Measurements
1.6.1 Exhaust Measurement
The emission analysis system shall sample and record dilute exhaust HC, CO, C0
2
, and NOx during
the transient driving cycle as described in ADR37/00.
1.6.2 Purge Measurement
The analysis system shall record the total volume of flow in litres over the course of the actual driving
cycle as described in part 3.Page A - 20
1.7  Emission Calculations
The emission  calculations remain the same as those used in the FORS Study except for the calculation
for HC emissions and fuel consumption. Hydrocarbon emissions and fuel consumption shall be
calculated by considering the ratio of propane to butane in the LPG blend and the respective HC
fraction and HC density as illustrated in the following equations:
HC
V HC
D
mix
mix HC conc
=
´ ´ ´
-
r 10
6
where Vmix
 (L) = volume of the mixture, equation of which will remain the same for LPG.
HCconc
 (mol ppm. carbon equivalent) = concentration of HC from emissions analysis.
D (km) = measured driven distance.
density of HC for propane = 0.6110 g/L and density of HC for butane = 0.6040 g/L
then density of HC for LPG test blend of 60/40,    rHC = 0.6082 g/L,
Fuel Consumption L km
HC Fraction CO Fraction CO Fraction
Fraction
mass HC mass CO mass CO
HC f
( / )
( ) ( ) ( )
100
10
2 2
=
´ + ´ + ´
´ r ´
where Density of LPG blend of 60/40 rf = 0.5300 kg/L
HC fraction for propane =  0.8170
HC fraction for butane  =  0.8270
HC fraction for the LPG test blend (60/40)
FractionHC = (0.8170 × 0.6) + (0.8270 × 0.4)
= 0.8210
FractionCO = 0.42880
FractionCO2 = 0.27291
and  HCmass = mass HC emissions in grams per vehicle kilometre.
COmass = mass CO emissions in grams per vehicle kilometre.
CO2mass = mass CO2
 emissions in grams per vehicle kilometre.Page A - 21
ATTACHMENT 3
Appendix 6
TUNING SPECIFICATIONS
General Requirements & Costs
The tuning will be undertaken by a separate contractor but on premises of the laboratory [if possible],
otherwise the vehicle will be taken to the contractor’s premises for servicing. The tuning contractor
shall be provided with the pre-test inspection checklist for that vehicle and any replacement parts
specifically ordered for the vehicle as a result of the pre-test inspection.
The parts budget for the tuning is set at a maximum of $150 per vehicle. Where it may be considered
necessary to replace expensive parts such as the oxygen sensor, and the total parts budget for the
vehicle will, as a result, exceed $150, the tenderer is authorised to approve additional parts
expenditure, subject to an absolute maximum of $200 [except where specifically approved by the
Project Manager], and provided that such extra expenditure does not lead to total parts expenditure
exceeding an average of $150 per vehicle.
Procedure
The vehicle shall be tuned to optimise operation on the LPG test blend of 60% propane and 40%
butane.
The tuning shall be limited to the following items [where applicable]:
· Replace points and air filter
· Replace oil [using SG20W-50 oil] and oil filter
· Check spark plug condition and gap, and adjust or replace as necessary
· Check distributor condition and operation and adjust as necessary
· Check and adjust idle mixture and speed
· Check and replace spark plug and distributor leads as necessary
· Check and replace hoses and other minor items in LPG fuel/electrical/emission control
systems as necessary, subject to budget
· Interrogate vehicle diagnostics and replace faulty components, subject to budget detailed
above.
Note Failed or malfunctioning catalytic converters shall be replaced, and faulty oxygen
sensors should be replaced where possible, if within running budget.
The transmission, radiator and battery fluids should be topped up if necessary.
Details of all work undertaken shall be recorded on the shaded area of the pre-inspection check list.
Range of Vehicles to be TunedPage A - 22
The vehicles which will be selected for testing/tuning shall be either Falcons or Commodores with
various types of LPG conversion kits [with the date of manufacture ranging from 1980-1991].Page A - 23
ATTACHMENT 4a
LPG Project Hand-over Inspection Sheet 1
(FILLED OUT BY NSW EPA)
Date:........../........../.......... Time:......... : .........am/pm
Owner’s Details:
Name:........................................................................
Address:....................................................................
......................................................................
......................................................................
Telephone:...............................................................
Reg. No.: Make: Model: Year:
ITEMS TO BE INSPECTED
Rego Label: ....../...../...... Coolant/Radiator Check:
Windscreen: Fluid Levels:
Mirrors (all): Wipers/Washers:
Tyres (all)/Hub Caps: Lights/Indicators:
Seat Belts: Smoke:
Interior Condition/HI-FI: Fuel Leaks:
Fuel Filler Cap: Oil Leaks:
Exhaust Check/Leaks: Battery:
Brakes: Spare Wheel/Tools:
Steering: Service Valve Operation:
Drive Line: Cylinder Inspection Date:
Vehicle OK for Testing: YES / NO
If NO, why?: ____________________________________________
____________________________________________
Fuel Type: Dual Fuel / LPG Only
Last Petrol Use: ........../........../..........
Inspection by (NSW EPA): ................................ ........../........../..........
Signature of Owner:  ................................ ........../........../..........Page A - 24
ATTACHMENT 4b
LPG Project Hand-over Inspection Sheet 2
(FILLED OUT BY LICENSED LPG SERVICING ORGANISATION)
Date:........../........../.......... Time:......... : .........am/pm
Reg. No.: Make: Model: Year:
Please Tick:
LPG Converter Make: Control System:
AIROD Closed Loop
BRC Open Loop
CENTURY
GRFT Conversion Kit Type:
IMPCO Fixed Venturi Flow
LANDI Variable Venturi Flow
LANDI HARTOG IMPCO/O.H.G. Carburettor
LANDI RENZO
O.H.G. LPG Conversion Kit Compatibility:
O.M.V.L. Components Compatible
OMNIGAS Components NOT Compatible
POLIAUTO
VIALLE LPG System:
Factory Fitted (Tickford)
After-Market Fitted
Other
Initial Modifications:
LEAK CHECK: ........................................................................................
Fit fuel bypass line to test vehicle.
Inspection by (Prospect Motors): ................................................................
LPG Licence No.: ................................................................
Time: ............................. Date: ............../............/.............
Final Modifications:
This vehicle has been inspected by a Licensed LPG repairer and is hereby certified
to be in a roadworthy condition for operation with LPG.
Inspection by (Prospect Motors): .....................................................
LPG Licence No.: .....................................................
Time: ............................. Date: ............../............/.............Page A - 25
ATTACHMENT 5:
Closed Loop vs Open Loop Technology in Engine Management Systems
Closed Loop Systems are continuously receiving information regarding the oxygen content in the
exhaust gases from the Lambda Sensor. This information feeds into the EMS which in turn adjusts the
amount of fuel being fed to the engine via the Steppermotor Valve to maximise emission performance
(stoichiometric air/furl ratio). If the air /fuel mixture is rich or lean, the EMS will adjust the air/fuel
mixture to achieve stoichiometry.Page A - 26
Open Loop Systems do not have any feedback mechanism from the exhaust gases and therefore
cannot adjust the air fuel mixture. A stoichiometric air/fuel mixture is established via the adjusting
screw at the converter. This mixture remains constant whist the engine is running. The air/fuel
mixture is not adjusted during normal operation.