EPA/AA/TDG/92-05
Technical Report
1992 Natural Gas Vehicle Challenge: EPA Emissions
arid Fuel Economy Testing
/ by -
Robert I. Bruetsch
Martin E. Reineman
June 1992
' NOTICE
Technical Reports do not necessarily represent final EPA
decisions or positions; :They are intended to present technical
analysis of issues using data which are currently available. The
purpose in the release of such reports is to facilitate the
exchange of technical, developments which may form the basis for a
final EPA decision, position or regulatory action.
U.S. Environmental .Protection Agency .
Office of Air and Radiation , . ,
Office of Mobile Sources
Regulatory Programs and Technology
Technology Development Group
:.': 2565 Plymouth Road
Ann Arbor, Michigan 48105
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Table of Contents
Page
I. Summary- ' . . . . . ' , 1 '
II. Introduction ........... 1
III. Test Program . . . . . . . ' . . . .2
IV. NGV Calculation Procedures . . . . . . .5
A. NGV Exhaust Emissions ........ 6
B. Modal Mass Corrections . . . . . .7
C. Modal Engine-Out Emissions . . . . .9
D. Natural Gas Fuel Economy . . ... . . 9
V. Vehicle Inspections & Maintenance . . . . . .10
VI. Test Results and NGV Challenge Scores . ... .13
A. FTP Tailpipe Emissions . . . . . .14
B. FTP Engine-Out Emissions . . . . . .... 17
C. Idle CO Emissions . . . . . . . . .18
D. Catalyst Inlet Temperatures . . . . . . 18
E. Combined EPA Fuel Economy . . ... . .19
VII. Conclusions . . . . . . . . . . .20
VI11. Acknowledgements . '.' . . . . . . . .21
IX. References . . . . . . . . . . . .21
X. Appendixes
A. CNG Fuel Analysis
B. .Example NGV Fuel Calculations
C. Sample Safety Inspection Form
D. Safety Inspection Notes
E. 1992 NGV Challenge Emission Test Schedule
F. Sample Emission Test Summary
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I. Summary
Students from eighteen universities in the United States and
four universities in Canada competed in an alternative fuels
engineering design competition called the 1992 Natural Gas Vehicle
Challenge. The objective of this -competition for each
participating, team was to convert a gasoline-fueled GM Sierra
pickup truck to natural gas operation and compete with students
from the other universities in the areas of exhaust emissions, fuel
economy, -performance, and design. Twenty of these twenty-two
schools made it to the competition with their dedicated natural gas
vehicle, and competed in all events.
The trucks initially underwent a safety inspection prior to
being emission tested at the EPA National Vehicle and Fuel
Emissions Laboratory in Ann Arbor, Michigan. The trucks were
tested for tailpipe and engine-out exhaust emissions, city and
highway fuel economy, and idle CO concentrations. The trucks were
then hauled to Imperial Oil (formerly Esso) in Sarnia, Ontario for
-29 ฐC cold start testing. While in Canada, the students 'competed
in a fuel economy road rally and made oral presentations of their
design work. The following day, the trucks moved to GM's Proving
Grounds in Milford. Michigan for vehicle range and endurance
testing. Cold driveability, 16% grade hill climb, and zero to 60
mph acceleration tests were also performed at the proving grounds.
Finally, vehicle design conversions were judged at the GM Technical
Center in Warren, Michigan. This report covers only the events
that took place at EPA.
II. Introduction
A student alternative fuels engineering design competition
called the "1992 Natural Gas Vehicle Challenge" was held April 22
through June 1, 1992. This competition was a followup to the 1991
NGV Challenge held last year'in Oklahoma. The 1992 competition was
held in Michigan and Ontario.
Like the first event, the major sponsors were the U.S.
Department of Energy, the Society of Automotive Engineers, the
General Motors Corporation, Energy/Mines and Resources-Canada, the
Canadian Gas Association, and the U.S. Environmental Protection
Agency. Last year, twenty-four (24) universities in the U.S. and
Canada competed with pickup trucks and conversion equipment from
GM. This year, Oklahoma and Florida Tech dropped out, and the
remaining 22 schools competed, many with newly developed systems in
an attempt to improve on last year's results. The main difference
this year was that the emission testing was performed at the U.S.
EPA National Vehicle and Fuel Emissions Laboratory (NVFEL) in Ann
Arbor, Michigan. Last year, emission testing was performed at the
National Institute for Petroleum Energy Research (NIPER) in
Bartlesville, Oklahoma.
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Special test procedures and calculation methodology .were
developed'by EPA for natural gas vehicles prior to the competition
which were reviewed and fine -tuned through several, iterations in
advance of the emission testing. This, methodology is covered in
detail in Section IV of this report. One valid Federal Test
Procedure (FTP) and Highway Fuel Economy Test (HFET) were performed
on each truck for official competition scoring purposes, and repeat
tests were only performed in the case of void tests, ,or when
vehicles were repaired, and the students were penalized for having
to perform vehicle maintenance. :
Due to the lack of engine-out testing capability in the
Evaluation and Test Procedure Development (E&D) part of EPA's lab,
testing was performed in one of the Certification (Engineering
Operations) test cells to make use of a modal analyzer for
obtaining engine-out and tailpipe- emissions on the same FTP.
Tailpipe emissions were determined by bag analysis of THC, .CO, C02,
CH4, and .NOx using standard emission analyzers. The THC analyzer
was corrected for its response to methane standard gases. Engine-
out emissions were determined by-modal analysis of THC, CO, NOx
sampled in equal exhaust portions from each bank of cylinders
before the first catalyst on,each truck.
The objectives of this test program were to successfully test
all CNG and LNG trucks submitted to EPA by the students for this
year's competition, and to compare their results to those of
similar gasoline-fueled trucks, and one of GM's dedicated natural
gas pickup trucks. Another objective was to interact with as many
of the students in the competition as possible.
III. Test Program -'',.
The test plan for this evaluation,program was proposed in 1991
and underwent a lengthy review process.[1] Approvals were required
from the directors of two different divisions, various support labs
within EPA, and the safety office. . ,
The NGV Challenge Steering Committee met roughly once a month
over the winter to resolve technical and budget issues. At these
meetings, the American Gas Association originally agreed to provide
commercial grade, odorized fuel supplies of both compressed natural
gas (CNG) and liquefied natural gas (LNG) on semi-truck trailers to
be stored outside of the NVFEL in the parking lot thoughout the
test program. . AGA also originally agreed to provide analyses of
the fuel composition, specific gravity, and heat content throughout
the refueling/testing at EPA. The Gas Research Institute (GRI)
also indicated (as late as January 1992) that they too would
support the provision of fuel to EPA for the emission testing. A
few months prior to the competition, the AGA had a change in
project management, and GRI reprioritized its budget and withdrew
their support for fuel supplies. This led DOE (Argonne National
Laboratory) to contact Tren Fuels, Inc., to solicit the use of one
of their fuel trucks, refueling-personnel and support services for
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the duration of testing. Tren Fuels had offered to support the
program last year, but the local Oklahoma Natural Gas Company was
chosen to do the job. Tren Fuels backed out of this year's event
when they learned that they would need to dedicate the use of a
fuel truck to the project in Ann Arbor for an entire month.
At that point, the emission testing deadline was drawina near
and students were preparing their trucks for shipment to EPA DOE'
whose responsibility it was to provide fuel for these e'vent^'
received an offer from Consolidated Natural Gas of Pittsburgh Pa
to use their CNG/LNG refueling equipment. This equipment wAich
had not yet been assembled, included a tank of liquid meShane from
Liquid carbonics of Geismar, LA, which would be connected to a
vaporizor recently purchased by Consolidated Natural Gas from Hvdra
Rig of Fort Worth TX, which in turn would be connected to a fuel
dispenser, provided, by DVCO of Longmont, Colorado. Consolidated
Natural Gas did. not have enough time to assemble and test this
equipment prior to the time it was to have been shippel to Ann
Arbor. As such, it was decided over a six-way conference call
between EPA, Argonne, and these four companies that SexpJct
everything to show up at EPA on time, be easily assembled Jnd
function like clockwork, would be logistically improbable^ At ?he
nthฐUr Li Caronics offered a ปore workable solution
me
another trailer of similar grade liquid methane, for one day to
SSJ *h% W, ฐOE *as contacted, and asked if there was any way to odorize
S! fjfl b.e.twซen the tube trailer and the vehicle fuel tanks dSr ing
this hn? nn? PฃฐCeSS- DOE could not offer any equipment to 21
this but did ship a calibrated methane gas detector to EPA it
S?hป C1HS? fcf gฐ Wlth the Liquid ^bonics fuels, and use the
methane detector to check all on-board fuel fittings, valves
regulators etc. as part of the pretest safety inspection At this
point, (April 29, 1992) , some trucks had -already- arrived for testing
and two test days had already been forgone. ,
^nl^w a*irival at tne EPA lab' trucks that had CNG in their
tanks were driven on a dynamometer until they ran out of fuel.
tfUfks were then Pushed out to the refueling trailer and
aPPrฐximately 1800 to 2000 psi. Each truck then
a safety inspection as described in Section V of this
hฐSe frUC*S that Passed inspection were then weighed on
>,v T ' v,SCaie located in the large soak area at NVFEL. Each
truck was then "prepped" for the official emission test. A vehicle
-ฐf.d5iving the vehicle ฐn a dynamometer over the
ฐf -an FTP test' i'e" a hot start LA-4
cycUc drvi h - ' '" a o
"soaiinad. tX g hschfdule lasting roughly 23 minutes, and then
soaking" the vehicle at the test temperature (68 to 86ฐF) for 12
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to 36 hours. Those vehicles that did not pass inspection, or for
whatever reason could not complete the emission test, were moved to
the bottom of the list, and student representatives were contacted
to come repair their truck.
The vehicles tested all started out as gasoline-fueled C2500
CMC 2-wheel drive 1990 Sierra three-quarter ton pickup trucks with
350 CID V8 engines. Control systems included EGR, air pump, three-
way catalysts, and closed loop fuel metering. They were also
equipped with 4-speed electronically controlled automatic
transmissions and posi-traction rear axles. The students then used
their own innovation (within the rules) to convert these gasoline
trucks to natural gas operation. An Equivalent Test Weight (ETW)
of 5000 Ibs. and an Actual Dynamometer Horsepower (ADHP) of 15.0 hp
were used to set the EPA.dynamometer on all tests of all trucks,
including the gasoline-fueled Sierra.
Each truck was tested over one valid FTP (engine-out and
tailpipe emissions) and one valid HFET cycle.[2] Time did not
allow duplicate testing, and for consistency, the same driver was
used on all official tests. After the HFET cycle (while the engine
and catalyst were still warmed up) an idle CO test was performed in
accordance with 40 CFR ง86.1527 through ง86.1544.[3] This
procedure allows a dilute sample of carbon monoxide to be measured
for not less than one minute, and no more than six minutes. For
this test program, typical sample time was five minutes as allowed
in the regulation.
The fuel was analyzed by Michigan Consolidated Gas Company
(MichCon) and determined to be 100 percent methane.[4] A copy of
the fuel analysis is provided in Appendix A. For calculation of HC,
emissions and fuel economy, the heat content and specific gravity
were also determined. The gross or higher heat content of the test
fuel was determined to be 1009 BTU/SCF on a dry basis. Historical
data of nationwide natural gas analyses were examined to .determine
a factor of lower to higher heating values. The factor was
determined to be consistently 0.9 in three different gas survey
references.[5,6,7] Therefore, the net or lower heating value used
in the calculation of vehicle fuel economy was 908 BTU/SCF. The
specific gravity of the fuel was 0.55 taking air as the basis,
i.e., the fuel was .a little more than half the density of air.
All vehicles were tested in the same test cell which was
equipped with both bag sample analyzers (for tailpipe emissions)
and a modal analyzer (for second by second and engine-out
emissions). The testing was conducted on a Clayton ECE-50 double
roll chassis dynamometer which uses direct drive variable inertia
flywheel and road load power control units. Gaseous emissions flow
from the vehicle tailpipe into a 350 CFM nominal capacity Horiba
Constant Volume Sampler and are separated into constituent sample
bags. Each truck was equipped with an engine-out emission sample
port which was located before the inlet to the first exhaust
catalyst and was designed to sample equally from each bank of
cylinders. The modal emissions bench consists of Horiba MEXA-9400
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and MEXA-9100EGR exhaust gas analyzers, a Horiba CVS-9100 constant
volume sampler, and a Hewlett Packard 3852A data acquisition
control unit.
Tailpipe hydrocarbon emissions were measured using a Beckman
Model 400 flame ionization detector (FID). NOx emissions were
determined by a Beckman Model 951A chemiluminescent NOx analyzer.
CO and CO, emissions were measured using Model A1A-23 Horiba
infrared analyzers. Methane (CHJ emissions were determined with
a Model 8205 Bendix methane analyzer. Nonmethane hydrocarbon
emissions were determined on a mass basis by subtraction of CH4
emissions from total hydrocarbon emissions. The correction factors
applied to the THC and CH4 analyzers for natural gas are discussed
in the next section of this report.
IV. NGV calculation Procedures
Procedures were developed for the determination of both total
and nonmethane hydrocarbon emissions, and fuel economy for natural
gas vehicles prior to the test program. Since the test fuel was
analyzed and found to be essentially pure methane, the nonmethane
hydrocarbon emissions measured are presumed to be mostly from the
consumption and/or combustion of lubricating oil. A discussion of
the procedures rip.vp."loped for nonmethane hydrocarbon emissions is
included below for completeness, and for use when determining NMHC
emissions from natural gas fuels that contain higher hydrocarbons
as well as those that are neat methane.
The test fuel was analyzed to obtain the mole percent
composition, including nitrogen, carbon dioxide, helium, hydrogen,
and hydrocarbons. These values were used to calculate specific
gravity and net (lower) heating value. This data was in turn used
to determine:
1. Composite H/C ratio for the total hydrocarbon components
in the fuel, H/CTHC;
2. Composite H/C ratio for all nonmethane hydrocarbon
components in the fuel, H/CNMHC;
' 3 Nonmethane carbon weight fraction (CWFNMHC) of the fuel,
grams of carbon per gram of nonmethane hydrocarbon,
excluding CO2 and inert gases not consumed in the
combustion process;
4. Mass fraction, grams of fuel per gram of carbon, where
carbon is based on carbon in hydrocarbon components (and
C02) in the fuel, g NGV fuel/g C in NGV fuel;
5. Energy density of the fuel in BTUs per gram of fuel,
expressed as net (lower) heating value, BTU/g NGV fuel.
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NGV Exhaust Emissions - Except for the calculations for
dilution factor, and the corrections for modal system mass due to
sampling, calculations for CO, CO2, and NOx exhaust emissions are
described in Section ง86.144-78, Title 40, of the Code of Federal
Regulations. [8] Because EPA has no published test procedures for
natural gas vehicle emissions or fuel economy, calculations for
total hydrocarbons (THC) , nonmethane hydrocarbons (NMHC) , and
methane (CH4) were treated as follows:
= CH4mass + NMHCra
Where: .
mass
NMHCmass = NMHC^ cor f NMHCCVS
CH4modat cor = CH4 mass correction due to modal engine, tailpipe,
and dilute sampling
CH4cvsmass = (Vm1x)(DensityCH4)(CH4c/106)
Where: .
Vmjx = Dilute exhaust volume @ 68 ฐF, 1 atmosphere
DensityCH4 = 18.89 g/ft3 @ 68 ฐF, 1 atmosphere
CH4c = CH4 concentration from the methane analyzer
corrected for the background methane
concentration
= CH4e - CH4d(l - 1/DF)
NMHCmodat cor = NMHC mass correction due to modal engine,
tailpipe, and dilute sampling
NMHCCVS mss = (Vmjx) (DensityNHHC) (NMHCC/106)
Where:
Vmix = Dilute exhaust volume @ 68ฐF, 1 atmosphere
DensityNHHC = 1.1771(12.011 + H/CNMHC(1. 008) g/ft3 @
68 ฐF, 1 atmosphere
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H/CNMHC = Composite H/C ratio of all nonmethane HC
components from the fuel analysis
NMHCC = Nonmethane hydrocarbon concentration corrected
for background ^concentrations and methane
response, using' total hydrocarbon and methane
analyzers
= NMHCe - NMHCd(l -1/DF)
NMHCe = THCe - (r) (CH4e)
THCe = Total hydrocarbon concentration of sample bag
from total hydrocarbon analyzer
NMHCd = THCd - (r) (CH4d)
= <0.01 if (r) (CH4d) > THCd
THCd = Total hydrocarbon concentration of background
bag from total hydrocarbon analyzer
r = CH4 response factor
= FID response to a CH4 standard/CH4 standard
= 1.163 for Range 14 of the THC FID
= 1.134 for Ranges 16 and 19 of the THC FID
DF = fx/fx + v/2 + 3.7-6fx + v/4n)100
C02e + (NMHCe + CH4e + COe)lCT*.
(Also applies to calculations for CO, CO2, and NOX)
Fuel = CxHy x = 1, y = H/CTHC from fuel analysis
NMHCcvsmass = <0.01 if NMHCC < 0
The total hydrocarbon analyzer (FID) was calibrated and
spanned with known concentrations of propane. Prior to the test
program, the total HC FID was spanned with known concentrations of
methane to determine the analyzer's resonse to methane. This
response, compared to the response to the propane standards, was
used to develop the FID methane response factors, or "r" in the
above equations. The Model 8205 Bendix methane (CH4) analyzer was
calibrated and spanned with known concentrations of methane.
Modal Mass Corrections - The CVS mass emissions per bag were
corrected for the amount of sample removed by the modal system
engine, tailpipe, and dilute benches. Corrections were required
for THC, CO, CO2/ and NOX emissions.
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The TEC results were corrected for the difference in hydro-
carbon density between gasoline and natural gas exhaust as well as
the TEC FID response to methane. The modal correction for TEC was
partitioned between CH4 and NMHC.
THCmodai cor = (THCm cor total) (D_ensityNG THC/DensityH/Ca1-85) ;
Where:
THCmodal cor = THC modal correction per bag' for sample
removed by the three modal benches
THCm cor total = THC mass correction per bag from the sample
removed by the three modal benches based
on gasoline exhaust density
DensityNG THC = THC exhaust density from an analysis of the
natural gas test fuel @ 68ฐF, 1. atmosphere
DensityH/c=1_85 = THC density for gasoline fueled vehicles
= 16.33 g/ft3 @ 68 ฐF, 1 atmosphere
CH4modal cor = (THC,^ cop) (Wgt. % CH4)
Where: . ,
CH4modai cor = CH4 modal correction per bag for sample
removed by the three modal benches
THCmodal .cor = Previously defined variable
Wgt. % CH4 = Weight percent CH4 from CVS bag analysis,
CH4pvs: mass/ (CH4cvs mass + NM^cvs mass)
cor
Where:
NMHCmodal cor = NMHC modal correction per bag for sample
removed by the three modal benches
cor
= Previously defined variable
CH4modai cor = Previously defined variable
reng, rtp, rdu = CH4 response factor from the engine, tailpipe,
and dilute benches
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= 1.00 from experimental response factor checks
on the three modal benches
No FID corrections for CH4 are required because all r factors
are =1.00.
Modal Enaine-Out Emissions - The modal system exhaust emission
calculations for hydrocarbons are based on the hydrocarbon density
of gasoline (indolene) with an H/C ratio of 1.85/1.0. To account
for this, the modal engine-out THC results are corrected for the
difference in hydrocarbon density between gasoline and natural gas
exhaust, and as necessary, the THC FID response to methane. CO,
CO, NO emissions do not require corrections.
2 * x
THCengb* = (THCengb) (DensityNGTHC/DensityH/c=1_85)
Where:
THCengb* = Total hydrocarbon mass per bag corrected for
density of natural gas test fuel
THCengb = THC mass per bag from the modal engine bench
based on gasoline exhaust HC density
DensityNG THC = THC exhaust density from an analysis of the
natural gas fuel, g/ft3 @ 68ฐF, 1
atmosphere
DensityH/c=1-85 = THC exhaust density for gasoline fueled
vehicles
= 16.33 g/ft3 @ 68ฐF, 1 atmosphere
rengb = CH4 response factor from engine modal bench
= 1.00 from experimental response factor check
No corrections to the THC mass for CH4 response were required
for this test program because r = 1.00 for the modal system engine
. bench.
Natural Gas Fuel Economy - The desired basis on which to
express the fuel economy of these natural gas vehicles is "miles
per equivalent gallon of gasoline." A sample calculation for NGV
fuel economy is provided in Appendix B.
MPGe = BTU/aal gasoline
NG BTU consumed/mile
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BTU/gal gasoline
(g C/mi)(g NG fuel/g C)(BTU/g of NG fuel)
Where:
BTU/gal gasoline = 114,132 BTU/gal (Indolene)
g C/mi = Grams of total carbon emitted per mile based on
weighted exhaust emission results, and CWFNHHC
from fuel analysis
= (CWFNMHC)NMHC + (0.749)CH4 + (0.429)00 +(0.273)CO2
. g NG fuel/g C = Reciprocal of carbon mass fraction based
on fuel analysis
BTU/g of NG fuel = Energy density determined by (0.9)
gross heating value on a mass basis
from the fuel analysis
V. Vehicle Inspections and Maintenance
Upon arrival at EPA, all trucks received a safety inspection,
and many repairs were made prior to preparing the trucks for their
official emission test. A copy of the ten page vehicle safety
inspection sheet is included in Appendix C. Basic descriptive
information was gathered on each truck, and each truck was checked
for current insurance and registration information. The truck body
was inspected for proper body and frame modifications, ride height,
driveshaft clearance, and the presence of a fire extinguisher. The
brakes, steering, powertrain, exhaust system, accessories, signals,
horn, lights, wheels, tires, and CB radio were all checked for
proper operation. Fuel system modifications were inspected
thoroughly for placement, mounting, valving, presence of manual
shutoff, refueling operation, fuel line integrity and routing,
regulator operation, and gauge operation. All trucks were started
on the inspection bay lift and leak checked at every exhaust and
fuel line fitting. Exhaust leaks were detected by covering the
tailpipe(s) and inspecting all clamps and fitting locations for
holes and/or escaping exhaust gas. All fuel lines, tanks, and
valves were inspected using a calibrated methane Gastrak detector.
Students whose trucks required maintenance prior to being
emission tested were contacted during the inspection. Those that
needed to send representatives to Ann Arbor (and/or could afford to
come) repaired their vehicle at the NVFEL. A total of eleven (11)
trucks out of twenty (20), or 55%, required maintenance in order to
successfully complete the emission testing. The vehicle safety
inspections were performed by Bill. Rimkus and Rob Liebbe of Argonne
National Laboratory, John Firment of GM's Advanced Product
Engineering Staff, and Rob Bruetsch of EPA. Copies of notes taken
during these inspections are included in Appendix D.
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Conversions were simple, ^J^^t safety problems noted in
t"if year's ePvaentais provided below.
Table 1.
-1th *~->Q"+ safety Problems
No. of Trucks
with ' Problem
Problem
. 6
invalid or No Registration
5
invalid or No Insurance
4
No CB radio
Empty or Inoperable Fire Extinguisher
Dead Battery '
Malfunctioning PCV System
Significant Oil Leak
Defeated "Service Engine Soon" Light
^functioning Wipers/Lamps/Accessories
Leaky Refueling Nozzle
Leaky Gas Cylinder .
Exhaust System Leaks
Inadequate Ride Height ^
Ruptured HP Fuel Line (Venting CNG tanks in Lab)
Unsafe Aspects of Fuel System Packaging
and in more detail in the
As seen in the last line item, a ^ safety concern
Appendix D, all trucks ^e written up^f some of t^se
related to fuel system ^jgrity. Exa P securely mounted
-ซ-ซซwซ -inoinded: high pressure fuel nnซ x,0Kris. wires and
4
3
1
2
1
3
20
re
concerns included; high pressure fuel iin debriS; &
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mounted securely, and fuel tanks in close proximity to exhaust
catalysts. '..""'
A total of thirteen (13) void tests were experienced. Eight
of these were instances where the truck could not complete either
the FTP or HFET cycle because of some problem with the vehicle.
Three of these instances were due to problems encountered with the
vehicle prior to the test, i.e., during a prep, or while the
vehicle was on soak. Two of the voids were due to sampling error
or analyzer malfunction. A chronological diary of the 1992 NGV
Emission Test Schedule is included in Appendix E. :;
Most trucks had some degree of oil leakage, as do many
gasoline vehicles. Four trucks exhibited greater than normal oil
leakage though, enough to cause safety concerns. Two trucks
exhibited high HC emissions and two tests were voided due to oil
leakage. One truck's dipstick had not been properly replaced in
its tube during maintenance causing oil to splash from the tube
onto an exhaust headpipe and ignite. The flame was quickly
extinguished, but the test was voided. Two :other trucks
experienced high HC emissions and substantial oil' loss due to
improper function of the vehicle PCV system. '
The exhaust leaks on the three trucks mentioned in Table 1
were all minor leaks which were easily fixed.at a local muffler
shop by tightening C-clamps and other fittings or plugging water
drainage holes. No welding was performed on vehicle exhaust
systems because the CNG tanks had to have fuel in them for the
vehicles to be transported to from the muffler shop.
Because the fuel was not odorized, gas leakage was of
paramount concern. As mentioned earlier, a methane gas detector
was used during vehicle inspections to check every fuel fitting on
every truck. Gas leaks were detected on two of the trucks. Both
of these trucks exhibited leaky refueling nozzles that had to be
replaced prior to the emission test. (Note:. Other trucks'
experienced some nozzle leakage after refueling which were detected
with soapy water. In all cases, however, the leak was due to dirt
or ice lodged in the nozzle seat which was able to be dislodged by
momentarily unseating the nozzle.) One of the two trucks also
leaked from the valve stem of one of its small auxiliary fuel
tanks. The leak was slow, and was detected while the vehicle was
still outdoors prior to the emission test. The tank was removed
and the vehicle was tested with the remaining fuel tanks.
A .near disaster was averted on the other truck which
experienced gas leakage. This truck had undergone considerable
maintenance, and had been road tested prior to refueling it to 2000
psi and bringing it back into the laboratory. Though this
supercharged vehicle was quite loud (subjectively louder than most
Diesel-powered pickup trucks), no vehicle malfunction occurred
during the road test. After it sat in the soak area for
approximately forty-five minutes, a technician started the truck,
and began backing it onto the scale for the pretest weighin.
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According to the technician, no one else was in that part of the
soak area at the time when suddenly she heard a loud pop and saw a
visible jet cloud of methane escaping from under the vehicle The
technician immediately turned off the vehicle and ran in the
opposite direction from the refueling bay telling everyone she
passed to evacuate the building. A contractor in the nearby
vehicle inspection bay saw people panicking and pulled the fire
alarm. The building was evacuated, while the gas rose to the
ceiling and dissipated through the air handling system Luckily
no methane ignited.- The truck was equipped with two tanks rouahlv
5 feet long and 13 inches in diameter that were connected at the
valve stems by a high pressure fuel line made of standard 1/4"
stainless tubing. After the tanks discharged, the truck vanished
outside and the fuel line was inspected. 9The problem appla?ef to
be that the 1/4" tubing was not properly inserted into iSSwaaelok
fitting. The tubing should rest firmly on the shoulder of tSe
fitting, and the nut should be tightened 3/4 of a turn (270ฐ) fo?
^hl^PfutlCUlar tUbe size-t9] Ifc ^s difficult to determine how
tight the nut was before the incident, but the tubing was crimSed
on the very end, indicating that it had not been inserted into IS2
fitting far enough. The fitting was repaired, the truck was
made)' and the test program wSs
^- A Postmortem analysis of the incident was performed which
indicated that roughly 60 Ibs. of methane vented into the soak area
(using the ideal gas equation with a compressibility factor of
z=0.8). Assuming perfect mixing occurred, the concentration of
methane in the large soak area was roughly 0.2% by volume, well
below the lower flammability limit for methane in air of 5.0%. Had
the fuel tanks discharged in the (much smaller) test cell or if
any ignition source had been present near the jet of methane, an
explosion could have occurred. The magnitude of the concern
expressed by EPA personnel is well founded since the energy
released by venting 60 Ibs. of methane is approximately equal to
the energy in 12.5 gallons of gasoline, 720 Ibs. of TNT or
slightly over 1000 sticks of dynamite. [10]
VI. Test Results and NGV Challenge Scores
In November 1991, the NGV Challenge Steering Committee
finalized the Official Rules of the competition and forwarded
copies to each of the competing universities. [11] The total points
possible for the competition was 1000, 250 of which were possible
from nust the FTP emission test. Another 100 points were possible
to be awarded from the combined EPA (55% city, 45% highway) fuel
Stf '~-SiuCe 35% ฐf the total Points were decided before
K ^ uthe EPA laboratory, the universities were more
lheir results on these tests compared to subsequent
Lven_ts: For example, two schools chose to forego the
i? l*Sl ln ฐrder t0 accฐinplish a valid FTP test,
cold s
because i 0 accฐinps a val
because the cold start event was worth only 50 points.
-------
-------
FTP Tailpipe Emissions - Included in the official rules
package was a description of the emission scoring schedule. This
emission scoring schedule is shown in Table 2. Teams had to meet
a minimum requirement in each of the emission scoring categories to
receive any points at all on the FTP emission test. Measured
tailpipe emissions used for scoring purposes were total
hydrocarbons, nonmethane hydrocarbons, carbon monoxide, idle carbon
monoxide, and oxides of nitrogen. A scoring schedule was also
included for particulate emissions (back in November 1991), but
particulate matter was not measured as part of this test program.
Table 2.
1992 Natural Gas Vehicle Challenge
Emission Scoring Schedule*
Pollutant
THC (g/mile)
NMKC (g/aiila)
CO (g/mile)
Idle CO (%)
NOx (g/mile)
PM (g/mile)
Your Score
Any
Pollutant
Greater
Than
2.93
0.67
10.0
0.50
1.7
0.13
0
Control Pollutant
Equal To Or Less Than
2.93
0.67
10.0
0.50
1.7
0.13
25
2.69
0.64
9.4
0.50
1.6
0.13
50
2.46
0.61
8.9
0.50
1.6
0.13
75
1.98
0.55
7.8
0.50
1.4
0.13
125
1.51
0.48
6.7
0.50
1.3
0.12
175
0.80
0.39
5.0
0.50
1.1
0.12
250
*ASTM roundoff rules apply.
LEGEND: THC = Total Hydrocarbons
NMHC = Nonmethane Hydrocarbons
CO = Carbon Monoxide
NOx = Oxides of Nitrogen
PM = Particulate Matter
The pollutant levels in the left hand columns of Table 2,
below which correspond to just passing with a score of 25, are the
most lenient interim standards currently being considered for light
heavy-duty (LHD) trucks, the weight class that these 5000 Ib. ETW
trucks fall into. The pollutant levels in the column to the far
right, below which correspond to obtaining the maximum possible
points of 250, are the most stringent future standards currently
being contemplated for LHD trucks.[12]
-------
-------
The "control pollutant" in Table 2 is the pollutant which is
the highest with respect to a given scoring category.- For example,
say a truck in the competition had tailpipe emission results of
1.63 g/mi TEC, 0.50 g/mi NMHC, 7.1 g/mi CO, 1.5 g/mi NOx, and 0.02%
idle CO. The emission score for this truck would be 75 points, and
the controlling pollutant is NOx. The pollutant levels of the
other exhaust constituents would put the truck at the 125 point
level, but NOx emissions are the highest with respect to the 125
point scoring category.
Table 3 contains the actual 1992 NGV Challenge Emission
Results, the emission scores, and the controlling pollutant for
each team. The teams are listed in the order in which they were
tested.
Table 3.
1992 NGV Challenge FTP Emission Results
and.Team Scores
Team
Illinois Tech
Ohio State
GMI
Tennessee
Colorado State
Northwestern
U of M Dearborn
Concordia
Toronto
Nebraska
Virginia
West Virginia
New York Tech
Cal State
Old Dominion
Texas Tech
Montreal Polytech
Maryland
Alabama
Texas
Gasoline Truck
FFP Weighted Emissions
THC NMHC CO NOx CO2
(g/mi) (g/mi) (g/mi) (g/mi) (g/mi)
1.75 0.07 0.1 3.4 459
1.03 0.01 4.9 0.2 531
0.59 0.01 2.0 0.1 523
2.57 0.06 17.0 1.3 490
0.69 0.01 '9.1 0.3 682
0.65 0.01 0.2 0.7 491
1.52 0.02 0.3 2.1 480
1.51 0.04 3.2 1.1 510
0.39 0.01 0.9 0.7 585
4.06 0.08 1.4 6.3 482
1.58 0.04 0.2 1.3, 561
2.66 0.09 0.2 6.7 474
12.45 3.27 54.6 <0.1 657
6.99 <0.01 46.8 0.2 537
3.61 0.41 5.7 2.6 542
1.31 <0.0l 5.2 l.l 750
OOR -- 42.6 3.0 503
1.49 0.02 0.4 1.3 628
1. 11 0.01 0.8 1.1 632
2.37 0.05 14.5 1.4 590
0.36 0.32 3.3 0.7 718
FTP Engine Out
THC CO NOx
(g/mi) (g/mi) (g/mi)
1.92 2.0 3.5
2.85 27.4 2.0
2.02 22.1 1.9
2.43 31.4 2.4
1.50 20.8 0.7
2.53 18.3 2.2
3.71 12.4 3.2
5.16 26.0 2.3
1.83 23.8 2.3
3.95 12.1 6.4
2.26 7.6 1.4
3.63 8.4 7.1
22.10 140.9 0.3
6.94 105.7 2.4
6.04 67.4 4.9
6.25 64.5 2.5
OOR 98.6 7.0
2.55 11.9 3.3
2.06 15.2 1.8
3.84 39.2 4.2
3.18 18.1 2.2
Idle
CO
(percent)
<0.1
<0.1
<0.1
<0.1
1.8
<0.
<0.
<0.
<0.
<0.
<0.
<0.
"
0.3
<0.1
<0.1
0.6
<0.1
<0.1
<0.1
<0.l
Emissions
Score
0
175
250
0
0
250
0
175
-250
0
125
0
0
0
0
175
0
175
175
0
--
Control
Pollutant
NOx
THC
CO
ICO
NOx
THC
NOx
THC
NOx
CO
CO
NOx
CO
CO
NOx
THC
CO
OOR=Out Of Range
-------
-------
Three teams scored the maximum points of 250 on the FTP
emission test and shared the award for Best FTP Tailpipe Emissions.
These teams are GMI, Northwestern and Toronto. Since these trucks
achieved the most stringent pollutant levels on the FTP test, there
is no control pollutant assigned to their emission scores. An
example of the emission test summary sheets provided to the
students during the competition is provided in Appendix F.
Nine (9) of the-twenty (20) trucks tested passed the FTP test
by obtaining the minimum requirements for positive points. (Last
year, only four (4) out of twenty-four (24) teams passed the
emission test.) Teams that passed this year tended to do very
well, i.e., eight of the nine teams scored at least 175 out of 250
points. Five trucks failed on the basis of high CO emissions, five
failed on the basis of high NOx emissions, and one failed the idle
CO requirement. As such, the control pollutant was evenly divided
between NOx and CO emissions.
Of the six trucks that passed the test but did not receive
maximum points, four failed to attain the most stringent
requirements for total HC emissions, one needed lower NOx
emissions, and the other was controlled by slightly high CO
emissions.
As mentioned earlier, the NMHC emissions recorded probably
resulted from the lubricating oil, since the fuel contained only
methane. NMHC emissions are included in Table 3 because they were
calculated based on the methodology developed and reported in
Section IV, and they show that natural gas vehicles can and do emit
higher percentages of NMHC emissions in the exhaust than is present
in the fuel.
The 1992 gasoline pickup truck tested would have passed the
test with maximum points of 250 had it been tested for competition.
purposes. This truck was tested to provide a baseline vehicle as
a target for the natural gas trucks to shoot for in terms of their
emissions performance. , The 1992 gasoline truck displayed
relatively high C02 emissions, second only to those emitted from
the Texas Tech truck.
Another vehicle which can be compared to the student
conversions as a baseline is the "Practice CNG" General Motors
natural gas vehicle tested in March 1992 prior to the student truck
test program. The results of the Practice CNG truck are not
included in Table 3, because the the test fuel was different and
analyzer calibrations were still being determined at the time it
was tested. As such, direct comparisons to the student truck
results are not possible. Nevertheless,, the Practice CNG truck FTP
emissions were 1.13 g/mi THC, 0.04 g/mi NMHC, 4.4 g/mi CO, 0.2 g/mi
NOx, and 576 g/mi CO2. These results would have been good enough
to pass the emission test with a score of 175 had this truck been
in the competition. The control pollutant in the case of the
Practice CNG truck is total HC which is above the 0.8 g/mi level
needed to attain 250 points. In addition to the example emission
-------
-------
test summary sheets provided to the students, the summary sheets
for the Practice CNG truck are also included in Appendix F.
Comparisons can also be made to the representative gasoline-
fueled 1990 certification test truck tested a little over two years
ago at EPA and reported on the 1990 EPA Test Car List. [13] The FTP
emissions of the 1990 Certification test truck were 0.26 g/mi THC
2.6 g/mi CO, 683 g/mi CO2, and 0.6 g/mi NOx. These results would
have been good enough to obtain a 250. point score, and are even
slightly better results than those obtained by the 1992 gasoline
truck tested during the student competition. Surprisingly, the
natural gas trucks did not weigh significantly more than the
gasoline-fueled trucks. All trucks actually weighed within the
specifications of the 5000 Ib. equivalent test weight class.
FTP Engine-Out Emissions - Best engine-out emissions was
determined by ranking the schools based on THC, NOx, and CO engine-
out emissions performance. Colorado State University and the
University of Virginia shared the award for the best engine-out
emissions as determined by their rank in these three pollutant
categories. This award was given out in order to recognize that
this was an engine design and development competition, and not just
a catalyst development program. As such, those that did well in
the tailpipe emission competition did not necessarily exhibit the
lowest engine-out emissions. Conversely, CSU and Virginia did not
obtain the highest points in the tailpipe emission scoring.
It is interesting to note that three teams; Tennessee,
Nebraska, and Cal State Northridge, measured engine-out THC
emissions that are lower than their respective tailpipe THC
emissions. This phenomenon indicates that the measurement
techniques for THC emissions are in error, but the magnitude of the
error is unknown. It is believed that the engine-out THC emissions
are more accurate than the tailpipe THC emissions because of the
relative inaccuracy of the correction factors applied' to the THC
tailpipe emission FID. As discussed in Section IV of this report,
the propane-spanned tailpipe, THC FID was corrected for both the HC
density of the fuel and for its response to methane standard gases.
The modal THC analyzer response factors were all 1.00. Therefore,
though precision in measuring tailpipe THC was maintained, it was
difficult to compare tailpipe to engine-out THC emissions with any
measure of accuracy. This situation would have also affected the
accurate determination of tailpipe NMHC emissions had the fuel
contained anything but methane. Had EPA procured the equipment to
do a full gas chromatogragh HC speciation, or calibrated and
spanned the tailpipe THC FID with known concentrations of methane,
the tailpipe THC measurements would have been more accurate. This
is an important observation with respect to providing input to the
development of test procedures for the Federal NGV rulemaking.
Also worthy of note, is that in no instances were engine-out CO or
NOx emissions less than the corresponding measured tailpipe levels.
The 1992 gasoline-fueled pickup truck exhibited the highest
THC conversion efficiency; 89 percent vs. 79 percent for the Texas
-------
-------
Tech natural gas truck. The average THC conversion efficiency for
the student converted natural gas trucks was 43 percent. Engine-
out emissions were not measured on either the Practice CNG truck or
the 1990 gasoline-fueled certification truck.
Idle CO Emissions - As mentioned previously, only one truck
failed the idle CO emission test. This truck was the Colorado
State entry with an idle CO measurement of 1.8 percent. Sixteen
(16) trucks measured.<0.1 percent CO at idle; two (2) trucks, both
of which failed the FTP on the basis of high tailpipe CO, measured
slightly higher idle CO than the sixteen just mentioned; and one
truck was not tested for idle CO because it did not complete the
HFET test.
The Colorado State truck, if judged on the basis of FTP
emissions only, would have passed with an emission score of 50
points, and its control pollutant would have been CO which measured
9.1 g/mi. The CSU truck displayed a catalyst CO conversion
efficiency of 56 percent over the FTP. The CSU truck exhibited
extremely high exhaust temperatures, on the order of 1500ฐF,
particularly in the latter stages of the FTP and throughout the
HFET test (i.e. , prior to the warmed-up idle CO test) . The thermal
wrapped exhaust head pipes on the CSU truck glowed cherry red when
warmed up. The exhaust system was monitored closely throughout the
testing, and a fire extinguisher was kept handy. Nothing ignited,
however, and the truck successfully completed the test sequence.
Catalyst Inlet Temperatures - In addition to engine-out
sampling taps, the students were asked to provide catalyst
temperature thermocouple taps at the inlet to the first catalyst in
the exhaust system. Thermocouples were installed by EPA at these
locations and catalyst inlet temperature traces were measured
throughout the FTP to determine what exhaust temperatures the
catalyst was exposed to throughout the trace. A catalyst inlet
temperature trace was also recorded throughout the HFET cycle for
those vehicles whose exhaust temperatures were elevated and caused
a safety concern.
It was not possible to determine when (if ever) the catalyst
lit off from these measurements. A better measure of catalyst
lightoff might have been obtained if thermocouples had been placed
at both the inlet and outlet of the catalyst systems, or if they
had been placed only at the outlet. Then a more definite
temperature rise might have been observed. Nevertheless, the
traces show what temperatures the catalyst "saw."
The typical temperature trace started off at room temperature,
and quickly rose to a more or less stable temperature regime
subject to some fluctuation with engine load. The thermocouples
worked on only fifteen (15) trucks. The other five either did not
function correctly or the exhaust tap did not exist. Of the
fifteen good traces, the time it took from the start of the test
until the exhaust gas temperature reached the stabilized regime was
typically 3 to 5 minutes. Stabilized temperatures ranged from an
-------
-------
average of 700ฐF at low loads tp 1000ฐF at peak loads. The hottest
stabilized exhaust temperatures were measured on the Colorado State
truck (1200ฐF to 1500ฐF) and the coldest stabilized exhaust
temperatures were measured on the Nebraska truck (390ฐF to 490ฐF).
The most unstable exhaust temperatures were exhibited by the
Montreal Polytech truck which varied throughout the trace from room
temperature to over 1000ฐF.
combined EPA Fuel Economy - The combined EPA fuel economy is
a weighted harmonic combination of 55 percent of the FTP (urban)
fuel economy and 45 percent of the HFET (highway) fuel economy
values as measured on their respective cycles. FTP, HFET and
combined EPA fuel economy for each of the vehicles tested are shown
in Table 4.
Also shown in Table 4 is the combined EPA fuel economy rank of
each truck that passed the emission test. Nine (9) out of the
twenty (20) natural gas trucks tested exceeded the fuel economy of
the 1992 gasoline truck, but only four of these trucks passed the
emission test. Table 4 shows Concordia University and Northwestern
tied for first with the highest fuel economy (15.3 mpg) when the
number is rounded off to the nearest tenth of an mpg.
All trucks also competed in two other fuel economy events
after the trucks left EPA; the road rally and the endurance test.
Only the nine that passed the FTP test were eligible to claim the
prize for Best Fuel Economy on the basis of these three events.
The eventual winner was Concordia University. Table 4 shows no
number for highway fuel economy for the New York Tech truck. This
is because the New York Tech truck failed to complete the HFET
cycle due to a leaky turbocharger gasket which caused a visible
flame to emanate from the passenger side of the engine under
sustained cruises over 55 mph. Therefore the FTP fuel economy was
used as the combined EPA fuel economy for this truck for
competition scoring purposes.,
The Practice CNG truck' provided by GM had a calculated FTP
gasoline equivalent fuel economy of 11.3 mpg. Highway fuel economy
for this vehicle, though tested, was never calculated with the
input data used at the time it was tested. Eleven (11) of the
student natural gas trucks had FTP fuel economies higher than the
Practice CNG truck. .
The 1990 gasoline-fueled Sierra pickup truck tested for EPA
certification measured fuel economies of 12.9 city mpg, 17.4
highway mpg, and 14.6 mpg combined. Five (5) of the natural gas
trucks had higher city mpg numbers, fourteen (14) had higher
highway mpg values, and nine (9) had higher combined mpg than the
1990 gasoline-fueled Sierra.
-------
-------
Table 4.
1992 NGV Challenge EPA Fuel Economy
Team
Illinois Tech
Ohio State
GMI
Tennessee
Colorado State
Northwestern
U of M Dearborn
Concordia
Toronto
Nebraska
Virginia
West Virginia
New York Tech
Cal State
Old Dominion
"exas Tech
Montreal Polytech
Maryland
Alabama
Texas
Gasoline Truck
FTP
FE
impel
(4.2
[2.2
12.5
12.6
9.5
13.4
13.6
12.7
11.2
13.3
11.7
13.7
8.5
10.5
11.8
8.7
8.7
10.4
10.4
10.7
12.3
HFET
FE
moei
21.2
19.5
19.3
21.5
14.1
18.4
20.3
20.3
18.4
19.6
17.5
21.1
-
17.9
18.4
18.2
16.8
16.7
16.5
16.6
18,2
Combined
FE
' mpg'i
16.7,.
14.7
14-9
15.5
11. 1
15.3 '
16.0
15.3
13.6
15.5
13.8 ..
16.3
8.5
12.9
14.1
11.4
11.1
12.5
12.5
12.7
14.4
:'";FE
-. ';;- Rank.
"'"" 4
'.' ... ' :
l~t:L.
': i
.'..6-
.'-- 5
..,.,9
7
7
-- '
VII. Conclusions . .
, A11 student team's natural gas trucks that were submitted to
EPA were successfully tested for the purposes of determining their
score.-in the 1992 Natural Gas Vehicle Challenge. ra-Ln-Ln9 e^
Nine out of the twenty trucks tested (45 percent) passed the
emission test. This is an improvement over last year's competition
where only four out of twenty-four trucks tested (16 percent)
passed the same FTP test. yซM.<-entj
*?* Toronto scored the maximum number of
ovr he FP cycle tha' lowt ซปiซions of all the universities
gaS trUCkS - exceeded the 1992 gasoline truck's
EPA fuel economy, nine exceeded the 1990 certification
-------
-------
gasoline truck's combined EPA fuel economy, and el^ror, ซซซ,* * **,ซ
GM Practice CNG truck's FTP fuel economy. e]-even exceeded the
The control pollutant on the FTP test was car-h ป *
six natural gas trucks, NOx emissions for another sฃ tฃฃฃ ?
hydrocarbons for four trucks and idle CO for one trunk '
trucks that passed the emission test with Lxlmu T nn-in^ ! J*1"?.
exhibit a control pollutant. maximum points did not
Colorado State and Virginia measured the lowest enaino ซ*-
iSS1CTn ^ baSlS ฐf thSir ""Kin* 'in the cate^orie^o? TฃC
NOx, and CO engine-out emissions. ซyuฃ-ies ot THC,
fuel 2cSnomy!a *"* Northwestern measured the highest combined EPA
Both LNG trucks passed the emission test and tied for sev^ni-h
in combined EPA fuel economy among those trucks that pawed?
The GM Practice CNG truck passed the emission test and would
have obtained a score of 175 points (out of 250) had it been testid
as part of the official competition. tested
t-v^i/L1 ftudent team's natural gas trucks had unsafe aspects of
their fuel system packaging which -were identified in the pretest
safety inspections. Most of the schools had to send
representatives out to EPA to perform maintenance on their
and others dictated repair instructions by telephone or ft
VIII. Acknowledgements
The authors wish to express special thanks to participants and
IX. References
^r-n- vm Robert z . "Test Plan: Dedicated CNG 1990 CMC
L Grav ?^ nT*? ^ ^2 NGV chal^nge,ป memorandum to Charles
Arbor?YMI January iT,1^^31 Protection Agency, ECTD/CTAB, Ann
2
Title40 llll ซซdScal J-SSt Procedure< Code of Federal Regulations.
iitie 40, Part 86, Sections 101 through 145, July 1, 1991^ " -
^1SoTef^ Procedure, Code of Federal Regulati
86, Sections 1527 through 1544, July 1, 1991.
40 P^<= ^1SoTef^ Procedure, Code of Federal Regulations. Title
40, Par -
-------
-------
4. McEachern, N. , "Gas Analysis Report," Michigan
Consolidated Gas Company, Run No. 92-223, April 29,. 1992.
5 . Obert , Edward F . , Internal Combustion Engines and Air
Pollution. (Third Edition), Harper & Row, Inc., New York, NY, pp.
235-242, 1973.
6. Taylor, Charles F. , The Internal Combustion Engine
Theory and Practice, Volume 2, MIT Press, Cambridge, MA, p. 121,
1985. . .'
7. Gas Engineers Handbook, American Gas Association,
Industrial Press, Inc., New York, NY, p. 2/48, 1965.
8. Exhaust Emission Calculations, Code of Federal
Regulations. Title 40, Part 86, Section 144.
9. "Swagelok Tube Fittings Catalog (Sizes 1/16" thru 1"),"
Swagelok Co., Inc.., Solon, OH, March 1992.
10. "Military Explosives," Department of the Army (Technical
Manual), TM 9-1300-214, Washington, DC, November 1985.
11. Larsen, Robert and W. Rimkus, "1992 SAE Natural Gas
Vehicle Challenge '92 Rules," U.S. Department of Energy, Argonne
National Laboratory, Energy Systems Division, Argonne, IL, November
15, 1991.
12. "California Exhaust Emission Standards and Test
Procedures for 1988 and Subseguent Model Passenger Cars, Light Duty
Trucks, and Medium Duty Vehicles," State of California,- Air
Resources Board, Title 13, California Code of Regulations, Section
1960.1, Sacramento, CA, August 30, 1991.
13. "1990 Fuel Economy Program Test Car List - Trucks," U.S.
Environmental Protection Agency, Certification Division, Ann Arbor,
MI, February 21, 1990.
-------
-------
X. Appendixes
-------
-------
Appendix A.
CNG Fuel Analysis
-------
-------
M I CHI BAN CONSOLIDATED GAS COMPANY
DATE ANALYZED: 04-29-92 _
S AMPLE INFORMATION
U.S.E.P-A.
CARL SCARBRO
LOCATION:
REQUESTER:
DEPARTMENT:
FIELD:
CITY.STATE:
PERMIT #
FORMATION:
SYSTEM:
OWNER:
PURCHASER:
RELATED TESTS: NGU TEST PROG.
ANN ARBOR MI
TUBE TRUCK # 3
CYLINDER I.D.
SAMPLE # '
SAMPLE POINT:
SAMPLE DATEQTIME:
SAMPLE RECEIVED:
ATMOSPHERIC TEMP. (F):
GAS TEMP. (F) :
GAS PRESSURE (PSIG):
WELLHEAD PRESSURE (PSIB)
FLOW (MMCF/DAY):
SAMPLED BY:
S.LAB.
FILL TUBE
04-30-92
04-30-92
4O
19OO
CARL SCARBRO
GAS ANALYSIS
GROSS HEATING VALUE (BTU/SCF)
^B^_>Bป*HซM^^ _^ป^ปMป^^^ป^^ป^ป"^^^^~^ ^^^ปซHป^ -I-- ""
WT. 7. 14.73 SAT / 14.65 DRY
MOL '/.
NITROGEN
CARBON DIOXIDE
HELIUM
METHANE
ETHANE
PROPANE
I-BUTANE
N-BUTANE
I-PENTANE
N-PENTANE
HEXANES
HEPTANES,
OCTANES
HYDROGEN
0 . OOOOO
O . OOOOO
O. OOOOO
1 OO . OOOOO
O . OOOOO
O . OOOOO
O . OOOOO
O . OOOOO
0. OOOOO
0 . OOOOO
O . OOOOO
O. OOOOO
O. OOOOO
O . OOOOO
O . OOOOO
0. OOOOO
0 . OOOOO
10O. OOOOO
O . OOOOO
O. OOOOO
0 . OOOOO
0 . OOOOO
O. OOOOO
O. OOOOO
O . OOOOO
6 . OOOOO
O . OOOOO
O. OOOOO
CALCULATED (IDEAL)
CALCULATED (REAL)
DETERMINED FIELD
/1 007
/1009
. SPECIFIC GRAVITY. .
CALCULATED (IDEAL) O.554
CALCULATED (REAL) O.555
DETERMINED FIELD
SULFUR (AS H2S) GR/CCF.. .
HYDROGEN SULFIDE
MERCAPTANS
SULFIDES
RESIDUAL
TOTAL SULFUR
OTHER
HYDROCARBON LIQUID (GAL/MMCF)
@58S PSIG & O DEG F
HYDROCARBON DEW
POINT (F 3 PSIG)
WATER DEW POINT
-------
-------
Appendix B.
Sample NGV Fuel Calculations
-------
-------
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Appendix C.
Sample Safety Inspection Form
-------
-------
1992 NGV CHALLENGE VEHICLE SAFETY INSPECTION SHEET
BASE VEHICLE INFORMATION
BASIC INFORMATION
Vehicle number
University name
Date of inspection
Mileage (mi/km)
Curb weight (Ib/kg)
Inspector's name
DOCUMENTS
Registration
Insurance
TRUCK BODY
Acceptable
Not Acceptable
Ride height within +- 2 cm of stock
- bottom of front bumper (stock: 38.84 cm)
- top of frame under cab (stock: 50.19 cm)
- top of frame at rear (stock: 77.90 cm)
- top of box (stock: 129.22 cm)
-------
-------
Acceptable Not Acceptable
UCK ROPY
No body modifications (except those approved by Tech Comm)
No trame modifications (except those approved by Tech Comm)
Fire extinguisher (type ABC, 5 Ib. minimum) mounted securely
to transmission tunnel with metal clamping system and
mounting bracket and driver accessible
Hood lock operation
Door lock operation
Window operation
Seat belt operation and routing
Seat adjuster operation
BRAKE SYSTEM
Pedal travel
Pedal firmness
Fluid level
No fluid leaks
Parking brake operation
ABS system operation
STEERING
No binding
No excessive play
No modifications to hardware
-------
-------
POWERTRAIN ^^^^te^ Not Acceptable
Neutral safety switch operation
Coolant level
Engine oil level
Transmission oil level
Power steering fluid level
Hose connections
Belt tension
No throttle linkage binding
Throttle return spring
"Service engine soon" light not illuminated
Diagnostic codes:
EXHAUST
No exhaust system leaks
No exhaust system interference
Catalytic converter heat shielding
Engine-out sample port (s)
Thermocouple fitting
VISION
Wiper operation
Wiper blade condition
Washer operation
-------
-------
Acceptable Not Acceptable
VISION rrngfH) . ; ;
Washer fluid level '.--'
Heater and defroster operation
.Air conditioner operation
No vision obstructions (except organizer-supplied sunscreen)
Low and high beam operation
Parking lamps
SIGNAL DEVICES OPERATION
Turn signal
Hazard light
Horn
Brake Lights
Reverse lights
40-Channel CB radio
WHEELS AND TIRES ' '
Stock tire size and brand (Michelin TPC LT 225/75R16)
Tread depth (minimum required is 4 mm)
Stock GM wheels in good condition
-------
-------
NATURAL GAS CONVERSION
Cyl. #
General information
Location
Manufacturer
Size (water vol.)
Material
DOT/CTC certification
Pressure relief valve
Manual cyl. valve
Cyl. #
General information
Location
Manufacturer
Size (water vol.)
Material
DOT/CTC certification
Pressure relief valve
Manual cyl. valve
-------
-------
_, . Acceptable No( Acceptable
Placement ' =====
Distance to exhaust greater than 8" or greater than 2" with
greater than 2" with minimum 1/8" steel shield
Distance to suspension/drive components greater than 2"
tor enure travel of component
Located between frame rails '
If located between axles, minimum 9" ground clearance
If not located between axles, above plane defined bv tire contact
and furthest rear/forward point, plus min. 9" ground clearance
No portion located behind rear bumper mounting face.
No portion located ahead of front axle. "
No contact with vehicle other than mounting hardware.
Mounting
No modifications/welding to cylinder shell.
Resilient gasket between tanks and clamping bands.
No weight supported by valves or connections.
Mounting must be able to sustain 20 times the weisht of the full
container in the longitudinal (fore/aft) direction, and 8 times the
weight of the full container in all other directions.
Clamping bands must:
Encircle entire cylinder at exactly two locations.
Have equivalent (or greater) strength of mild steel with
thickness of 5 mm'and width of 31 mm (not including
bolt holes.)
Have corrosion-resistant coatings on bands and mounting
hardware.
Have mounting bolts equal to or greater in strencth to
12 mm (0.5 in) Grade 5 steel bolts.
Mount to the vehicle through minimum 2.5 mm steel sheet,
or sheet metal with equivalent strength 6 square inch
backing plate.
-------
-------
Clamping bands must: (Cont'd) Acceptable Not Acceptable
Provide no point loading and be mounted squarely to the
cylinders' skin.
FUEL SYSTEM VALVFNG
Pressure and Temperature Relief
Located 8" (or more) from exhaust, or greater than 2" and shielded
with a minimum of 1/8" thick steel sheet.
No shut-off valves that can isolate the relief valve from the
cylinder it is venting.
Cylinder Storage Valve
Located 8" (or more) from exhaust, or greater then 2" and shielded
from the heat source by a minimum thickness of 1/8" steel sheet,
securely mounted.
Located a minimum of 2" from suspension components through
enure suspension travel.
Must be shielded from debris thrown up from the road by a firmly
supported shield that doesn't interfere with the cylinder, valve, or
fuel lines.
Cylinder must be oriented such that valve is on the most protected
end of the cylinder. -
Fuel Lock-Off Valve .
Operation must be automatic to prevent fuel flow to the engine
when it is not running, even with ignition on.
Located on high-pressure side of the first stage regulator as close
to the cylinder as possible.
-------
-------
Accqxablc Not Acceptable
' Master Mnnnal Shut-Off Valvp. .
Must he manually-operated one-quarter turn valve, open when
pointing towards, the front of the vehicle.
Truck must have a label directly above the location of this valve.
The label must indicate the location, and have a directional arrow
as to the operation of the valve. The label must be colored to
contrast the vehicle color and be a minimum of 3 by 3 inches. The
label shall also be marked with the words "MANUAL SHUTOFF
VALVE" in letters at least 1 inch tall.
Valve must be located directly below NG refueling receptacle.
REFUELING FITTING-
Must be Sherex Part No. 1000/1020/1040
Must be located under stock gasoline filler door.
Must be mounted securely to the body of the vehicle.
Must be supplied with a dust cover.
FUEL LINES /HIGH-PRESSURES
Material
(All of the material criteria are met by stainless steel tubing sized
either 1/4" x 0.035" wall, or 3/8" x 0.049" wa}l.)
No use of aluminum, copper, plastic, cast iron, or galvanized
tubing or fittings.
(except for alloys containing greater than 70% copper or non-
sparking aluminum alloys)
Must be labeled or tagged with material and working pressure.
Must be rated for bursting pressures at least 4 times greater than
maximum rated service pressure.
Must not be flexible hose.
-------
-------
Routing
No kinked lines.
No routing oflines within 2" of driveshaft tunnel.
^^
sheet metaj or
should be located or shielded so a, to be protected from road
** .the "ul;k Cll"=r *
eisht tachK from
Located in directly accessible places.
ied to all male
requireraenis (ie-
Standard ซ,4,
Compression fittings raust be used for ^ [uWng
-------
-------
Acceptable
Not Acceptable
Exterior
Must ho located under the fuel filler door.
Must be mounted .securely ;o the body of the vehicle.
Interior .
Must not allow gas flow into the cab in the event of failure.
Must be mounted securely.
UNDERHOQD COMPONENTS
Pressure Regulators
Mounted securely to truck body.
No regulator weight may be placed on the attached gas lines.
Must be installed in an easliy accessible location.
Must be protected from contact with electrical equipment.
Fuel Lines
Do not come in contact with any underhood component except at
fittings. .
Must either be routed greater than 8" from battery terminals, or
insulated against electrical contact.
-------
-------
Appendix D.
Safety Inspection Notes
-------
-------
Illinois Institute of Technology
inspected on 4/23/92
Insurance expired on 9/1/91 : -
Fire bottle not securely mounted to floorpan . ... ',
Engine coolant low ' :
Rear cylinder brackets loose
Metal bracket to tank contact on all three tanks
Paint worn off end of large tank
Clearance to KR cylinder valve only 1/2"
Bare wires below frame rail on left
Fuel lines remaining from gasoline system rattling against tank on
left
No high pressure lock-off solenoid
Manual valve between tanks and engine
Superfix wire laying on top of engine
Regulator coolant hoses not supported are laying on engine
.Low pressure fuel supply line laying loose on brake reservoir
-------
-------
Ohio State University
inspected on 4/23/92
RR shock close to exhaust
contact between valve on furthest rearward tank and faody
cable to LH pup converter chafing on brake Une and frame
Manual shut-off mounted to thin sheet metal
High pressure fuel line unprotected on cross.e.ber under cab
No power steering flui.d
Battery cables hitting on LH inner fenderwell edge
and
-------
-------
University of Tennessee
inspected on 4/23/92
Team came out on 4/27/92 with Camet technician to re-wire pre-
heated _ catalysts. Found that catalysts were not drawing down
batteries, that some relay was staying energized and drawing 5
amps. Fixed some other safety problems.
When T/C was being put in, an exhaust leak was detected. Rob
Liebbe drove vehicle to local Midas shop, where* they tightened some
C-clamps and said that no more leaks were present.*
fixed - Dead battery
Engine oil 1/2 quart overfill
Axle to tank clearance less than 1" at full jounce
Right side tank bolts not Grade 5
High pressure fuel line near filler door not secure
Frame material near rear of fuel tanks removed
fixed - cables near transmission shift linkage hanging loose
fixed - Red wire near end of OD transmission hanging loose
Manual shut-off valve rated only to 3000 psi
-------
-------
University of Michigan at Dearborn
inspected 4/24/92
Team came to pick up truck on 4/28/92 at 8:30 am, dropped off
on 4/29/92 at 3:00 pm. Fixed rear axle jounce by^nstallna
resilient 1-1/2" pad at contact point . between axle and fra-e
shielded front of RH Comdyne tank, moved HP line away from heaSer's !
No registration documents
ECM not mounted securely in glovebox
Coolant on intake manifold
Engine oil low
Flexible hose :on high pressure side of system
Insufficient clearance from driveshaft to cylinder and valves i-~
rear axle under full jounce conditions axve^ _^
Single tank mounting strap for two cylinders forces tanks
with point loading
fixed - Right Comdyne tank within I" of balance tube of exhaust
fixed - High pressure fuel line passes within 1" of RH exhaust
header
No lock-off solenoid
-------
-------
GMI Institute .
inspected on 4/24/92
No vehicle registration
A/C inoperable
Throttle cable chafing on plug wires
Thermal wrap on LH'catalyst is falling off
CNG label not on outside of truck
Front of Comdyne tank is within 1/2" of driveshaft with 'no hoop
Rubber gasket not completely around Comdyne tanks
Grade 0 bolts used for mounting tank brackets to crossmember
Left center tank mounting strap bolt within 1/4" of'frame edge
-------
-------
New York Institute of Technology
inspected on 4/24/92
Team came to EPA on 5/4/92 to fix .safety problems and PCV valve
Team needs to come out to fix PCV system before emissions, testing
Arrived by driving to EPA at 4:30 pm on 4/24/92
No insurance or registration
No CB radio
Rear brake line from frame to axle is laying on LH exhaust
Ground' cable to rear battery rubbing on RH frame rail
Engine-out sample port not connected to outside
A/C system disabled and flopping on frame
Underhood regulator cooling hose rubbing on inner fenderwell edge
Glass jar used for crankcase vent catch jar
Positive battery cable rubbing on MSD module heat sink
.Coolant overflow bottle not supported firmly
Fire bottle not secuely mounted to floorpan
Switch on dash below radio needs to be disabled
Service Engine Soon light is disabled
Frame rail to turbo-out exhaust contact
Lock-off solenoid on low-pressure side of first stage regulator
Second stage regulator out fitting hitting on inner fenderwell
Open wire connections below and aft of intercooler
*
Red wire to cooling fan relay hanging loose and passing through
body without a grommet .
Oil leak from rear of engine
PCV system open to atmosphere
-------
-------
University of Maryland
inspected on 4/27/92
Insurance expired on 6/30/91
RH and LH manual shut-off valve not accessible
Vapor fuel line hitting brake line mount adjacent to transmission
Catalyst to transmission crossmember interference
Engine oil leaks at nylon line for oil pressure and on RR of engine ''
-------
-------
University of Texas at Austin
inspected 4/28/92
Team is coming out on 5/5/92
Use of nitrous oxide ?
Throttle cable unprotected where it is unsheathed
Bare, dangling wires to fuel lock-off solenoid
Service Engine Soon light defeated
Spare tire mount crooked
No registration or insurance
LR tire rubbing on exhaust
Exhaust hanger behind muffler on LH side is dangling
Mount for exhaust at this hanger should not be thermal wrap
Sra^er33^ ^ ^ -transmission crossmember is hitting
A/c hose rubbing on RH inner fender edge
A/C hose rubbing on blower tensioner pulley
A/C lines held on, by hose clamps
A/C hose near blower tensioner pulley is almost out through
- * -et
Beaded tightly into
held 3Way frฐป bl b.lt loosely with
T/C lead is dangling near front of blower
PCV system is disabled
Red wire from positive side of battery runs close to regulators
engine aSSSt "* VaCU advance ""=3 are not supported across
-------
-------
Fire bottle mounting bracket not secure to floorpan
Coolant overflow bottle not secured
Position switch for WOT hitting on fuel line for NOS operation
Windshield wipers and washers inoperable .
Reverse lights flicker
Push button switch in cab below radio needs to be disabled
No high pressure lock-off solenoid
Manual shut-off is between tanks and engine
High pressure fuel line hitting frame as it goes into the engine
compartment
Teflon tape used on manual shut-off
RR-emergency brake cable hitting on LH side exhaust
Ground clearance on front catalysts only 8"
Ground clearance on engine-out tap only 5-1/2"
-------
-------
Colorado State University
inspected 4/28/92
Team out on 5/1/92. to recalibrate EPROM for lower altitude oer
six hours burning EPROMs, adjusting fuel rail pressure and'drivira
vehicle for computer to learn new '
fixed - RH exhaust hanger broken
fixed - Driveshaft containment is not a hoop
Manual shut-off is between tanks and engine
Bushings on bottom mount of rear shocks are loose
fixed - Engine-out line after T-fitting is loose '.-.-'
Crossmember at bed/cab junction is not reinforced for side impact
Brass fitting on high-pressure side (HOKE manual valve)
High pressure fuel line passes within one inch of exhaust headers
on both LH and RH sides
Fire bottle mounting bracket not secured to floorpan
-------
-------
University of Nebraska at Lincoln
inspected on 4/28/92
Member of last year's team came out on 5/1/92 from Tech.Center to
fix coolant fitting.
fixed - Nylon coolant T-fitting ruptured -
Hose clamp on LH turbo-out to engine is on edge of hose
Exhaust of LH and RH sides hits front of leaf springs
Rear of Pressed Steel tanks is within 1" of exhaust (shielding is
provided) .
Aluminum shield is contacting high pressure line coming off LH
Pressed Steel tank
RH Pressed Steel tank valve 1-1/2" from RR shock
RR shock 1" from high pressure line
Lock-off solenoid on low pressure side of regulators (NEMA Class 7
explosion-proof solenoid is used)
Operation of push-pull manual shut-off not positive
Foil shielding on rear of Pressed Steel tanks is loosely attached
Front spring spacers are used
Service Engine Soon light is defeated
-------
-------
Concordia University ;
inspected on 5/1/92
Rear cylinder valves interfere with rear brake line.
Emergency brake cable hits high pressure fuel line coming from TF
cylinder . *^ ^-j-'-'i.i -r .
fUeling line Passes through sheet metal without a
Teflon used on cylinder valve fittings
Fuel lock-off solenoid on low pressure side of regulator
-------
-------
Northwestern University
inspected on 5/1/92
Team first dropped off vehicle on 4/30/92.
Team worked, on vehicle to. remedy shift linkage contact, leaking
Hansen fitting. They also burned a new EPROM for their truck.
Fire extinguisher not mounted to transmission tunnel.
fixed - Shifter linkage contacts high pressure fuel line.
fixed - Auxilliary Hansen fueling connection contacts frame, is not
protected from road debris, and leaks.
-------
-------
University of Toronto
inspected 5/4/92
Heat shield at front of RH cylinder hits HP fuel'line inside frame
rail
HP fuel line within 1" of engine-out tap on RH frame side rail
Loose hose clamp at T-fitting on hose coming off rear of manifold
Spark plug wires laying on engine-out tap lines
Regulators not attached to body of truck - supported by fuel lines
Wire bundles hanging below frame ' ,' .
Large RH cylinder less than 2" from exhaust (with Alrshield)
Three cigarette lighter plugs in cab need to be covered
Landi Renzo switch needs to be covered,
Box with switches behind seat needs to be covered
-------
-------
1
Ecole Poly technique de Montreal
inspected on 5/4/92
HP fuel line less than 2" from exhaust pipe under bed
No registration or insurance papers
Fire bottle .needs charging
on rubbar
Lock-off solenoid on low pressure side
Hot alternator lead lays on pressure regulator
Wiring bundle is tied to high pressure line underhood
their mounting system - not firmly
lountl" Sฐlen0idS bounce
No freon in A/C system
Many loose underhood wires
Cylinder heat shielding is attached with duct tape
Exhaust system hangers mounted to sheet metal under bed
d ซ crossmember on ,
Wire hanging on small rear cylinder's valve
contact on
Differential gasket leaking
T/C leads hanging loose in cab
ECM and other electronics mounted loose in glovebox
Switch in cockpit needs to be covered
Manual shut-off between tanks and engine
Manual shut-off not securely attached to frame
No CB
-------
-------
Shift linkage within 1/4" of HP fuel line
HP fuel line not secure from manual shut-off to engine compartment
(in area of shift linkage)
Dead battery ' .
Fuel line from refueling fitting that passes through hole in frame
is protected only loosely.by a split hose - needs a grommet
Rear cylinder less than 2" from axle housing under jounce
-------
-------
California state University - Northridge
inspected on 5/5/92
Sherex fitting leaks -
Engine fuel feed line is rigid with no stress relief from regulator
to engine (problem under engine's reaction to torque)
PCV system inoperative - crankcase builds positive pressure
(possible fix is LH valve cover to manifold vacuum, RH valve cover
to filtered fresh air source)
Large catalysts hit on frame on both sides
High pressure lines not secured to frame - hit on RR above tire, on
crossmember behind cab, on LH frame rail in vicinity of
transmission
Fitting comes in contact with middle right cylinder's surface
Bed reinforcement (U-section) cut away for clearance of a tank
mounting crossmember
Rearmost LH side cylinder valve within 1" from shock
Crossraember that the front of the 2 rearmost cylinder brackets bolt
to is not securely bolted to the frame rails
Front LH cylinder has contact with a crossmember at a third point
(gasket material sandwiched in between)
Not clear from outside of truck which is the main manual shut-off
valve
Hanger for rear of LH muffler hanging loose
Fire bottle loose
Parking brake inoperative
No CB
Spark plug wires contact SS engine fuel feed line
Exhaust system header on LH side contacts frame
Regulator contacts hot lead off battery
-------
-------
Univoraity of Virginia
inspected 5/12/92
wiring adjacent to underhood fuel pressure gauge
Wiring grounded to fuel control unit .
Interior wiring needs to be secured
CB radio loosely mounted
LH side fuel lines and brake lines loosely mounted
LH catalyst not properly heat shielded
Rear tanks contacting under bumper/hitch with no crush space
Rear left tank manual valve within 2" of differential housing under
full jounce
Right side fuel line loose on frame and contacting frame
Manual shut-off valve located 15" back from door edge on under-
floor crossmember and hidden
Teflon tape '
Plastic fuel line hangers '
Fuel lock-off integral with pressure regulator
Driver side battery terminals are loose
-------
-------
West Virginia university
inspected 5/12/92
Fire bottle not mounted to transmission tunnel
Manual shut-off directly under door handle on frame
No CB radio
Manual cylinder valves are hard to access
Frame modifications for tank mounting points approved ?
Emergency brake cable chafing on exhaust near rear axle
Emergency brake cable chafing on left side cylinder
Fuel line crossing from tank to tank unsupported and above
driveshaft
Fuel line not supported and has excessive flex from manual shut-off
valve to fuel door
Right side exhaust pipe ground clearance less than 8"
-------
-------
Old Doainion University
inspected 5/13/92
CB radio interferes with removal of fire bottle
No fuel pressure gauge at filler door
Fuel line from tank to engine within 8" of catalytic converter with
no shielding
Possible point load on right cylinder at rear where clamp bolts
together *
Valve shielding mounting is insecure
Several fittings are inaccessible unless tanks are removed
Upper radiator has electric tape wrapped around it near valve cover
-------
-------
Texas Tach
inspected 5/19/92
Truck under-body modified for tank clearance
Left tank rear valve shield axle interference
Left frame brake line support clip broken permitting line to chafe
against bolt head
Lines not labeled as to working pressure
Spare'tire loose in bed
No windshield washer operation on passenger side
Power steering fluid low
RR taillight lens loose
Underhood red pressure regulator supported by fuel lines
-------
-------
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jy^^^^jffjj^fs;'^
:^^^K^mm^^-
' -"" ' >r - "jl..!^ s*-~-.-~ ' **"*;/r*~ฃ^>*?~t.~"_^.
.:.'-.':. .'"r:~iSJ'--;!-Sfl?i33S;-Sf'rSFrf!i
'":.':''-''1'7ri'-:-^'~ ''1-Ji.l"'i4"4S'V^?7-f!f- '
. ป-... w. ,.. -. .
".-.: ,. .","?1,'.' -. ' ''- - " -'-.." '"'_' ',..""'"'"-
-'-.-'"-" IT ' '*.'. I' u "' ''.%r"^--,'.^i::'*T ^V
''
-------
-------
1992
April 26 - June 6
NGV Test Schedule
1992
1 "'..'NDAY
i April 26
i
1
i
!
May 3
i
t
I May 10
May 17
t
May 24
-Vlclv J i
i.otu Dnveabiiitv
"citing i Milfo'rd)
<>' c Grade Hill
C.'.imb C%ent
Milfordl
Vceleration and
->;>unu Testing
Millord)
Lai i Revised
MONDAY
April 27
May 4
Prep UM-Dearbom
Prep Colorado
State
Prep Northwestern
May 1 1
Reprep Nebraska
Prep West Virginia
Prep Virginia
-
May 18
Prep Texas Tech
Prep Montreal
Polytech
May 25
Memorial Day
Holiday (LT.S.)
T i
June 1
Design Judging/
Presentations
Vehicle Display @
GM Tech Center
Awards Banquet
(Novi Sheraton)
L
TUESDAY
April 28
May 5
Test UM-Dearbom
Test Colorado State
(HFET Void)
Test Northwestern
Prep Nebraska
Reprep Colorado
State
May 12
Retest Nebraska
Test West Virginia
Test Virginia
Prep Texas
Reprep Toronto
Reprep New York
tech
May 19
LNG Fuel Arrives
Test Texas Tech
Test Montreal
Polvtech
Test Virginia (Hot
505 Only)
Prep Maryland
Cold Start Testing
Begins (Samia)
May 26
Prep Gasoline
Truck (Second
Test)
Retest Alabama
(HFET Only)
June 2
SAENGV
TOPTEC
Meeting (Novi
Sheraton)
WEDNESDAY
April 29
CNG Fuel Arrives
Prep Ohio State
Prep Illinois Tech
May 6
Test Nebraska
(Void)
Retest Colorado
State (Void)
Prep Concordia
Prep Toronto
( Failed )
May 13
Test Texas ( Void)
detest Toronto
detest New York
Tech (HFET
Void)
'rep Old Dominion
Repreo Cal State
Reprep Tennessee
May 20
"est Maryland
leprep Texas i Fuel
Vented)
econd Car Hauler
Leaves tor Sjrnia
May 27
Test Gasoline
Truck (Second
Test)
Reprep Texas
June 3
THURSDAY
April 30
Test Ohio State
Test Illinois Tech
Preo Tennessee
PrepGMI
May 7
Test Conco'rdia
Prep Cal State
(Failed)
Reprep Toronto
Prep New York
Tech ( Oil Fire-
Void)
May 14
Test Old Dominion
i Sampling Void)
Retest Cal State
Retest Tennessee
t L-' 1 U /tpliA
Reprep Old
Dominion
Reprep Colorado
State
First Car Hauler
Leaves for Sarnia
May 21
Test New York
Tech (HFET
Only-Void)
Prep Alabama
Prejj Gasoline
Truck
May 28
Retest Texas
End of Emission
Testing
Last Car Hauler
Leaves tor Samia
Cold Stan Testing
Ends (Samia)
Other Competition
Events Begin
(Samia)
June 4
FRIDAY
r
Mav 1
Test Tennessee
Test GMI
May 8
Test Toronto
(Analyzer
Failure-Void)
May 15
Retest Old
Dominion
Retest Colorado
State
May 22
Test Alabama
iHFET-Void)
Test Gasoline
Truck
Third Car Hauler
Leaves tor Samia
May 29
Road Rally ( Fuel
Economy
Competition)
Design Judging/
Presentations
Hot Dnveabiiitv
Testing
June 5
_
SYTURD \s '
Mav "
'
1 May 9
May76
May 23
May 30
Vehicle Ranee,'
Endurance
Testing (.Milloru,
June 6
i
6 In
-------
-------
Appendix F.
Sample Emission Test Summary
-------
-------
1.51
1992 NGV CHALLENGE
EPA EMISSION AND FUEL ECONOMY RESULTS
CONCORDIA
TESTED 5/7/92
FTP
TAILPIPE EMISSIONS
0.04
3.2
1.1
509.9
FUEL ECONOMY
THC
ig/mi)
*
NMHC
fg/'mi)
CO
(g/rai)
NOX
(g/mi)
CO2
(g/mi)
FTP
mi/gal
HFET
ml/gal
COMBINED
(.55/45)
tmi/gal)
12.7
20.3
15.3
FTP
ENGINE-OUT EMISSIONS
CO
(g/mi)
26.0
NOX
fg/mi)
2.3
IDLE
CO
EMISSION-
SCORE
175
-H=S TCST CONDCCTED AT TTC f.5. EPA NATIONAL VEHICLE AND FUEL EMISSIONS LABORATOR CD . yy
* Controlling Pollutant - ---
v[
Processed
-------
-------
NATURAL GAS VEHICLE TEST ANALYSIS
Dyno: 0005 Test No: 922458
est No. MFR
- .r ~i 5a 40
Ovno Analvzer
- -05 . . -4003
3vno.CVS VMIX
Bag 1 2544
Bag 2 4484
Bag 3 2610
Dist Units
ฎ
Inout
Vehicle ID
^.oncoraia
CVS
'.todai
Distance
.3.6
3.36
3.59
page i 3
Processed: 05/27'92 12:54.
Data for Concordia
Vert Version Test Date
^ ? " Q r>
Exhaust
HC FID
Bag 1
Sag 2
Bag 3
Range
; 4
' 6
Meter
33.2
54.6
36.3
Background
Range Meter
'5 0.9
'4 3.3
'5 03
Key Start
3'56
' Test Type Procedure
Ambient Conaitions
Barometer 29.44
Ambient ~5 5
Dew Point 45 S
Terno Units r
i HH Fin
Bag 1
Sag 2
Bag 3
CO .1 .
Bag 1
Bag 2
: Bag 3
: CO2
: Sag 1
Bag 2
Bag 3
NOx
Sag 1
Bag 2
Bag 3
' 6
18
23
23
23
3 4
27. 1
56.8
39
50.6
15
< 5
27.3
48.9
53.4
'3 ; 5
. < ฐ : . ;
ia '0.3
23 1.9
23 '.8
23 1.8
Bag 1
Sag 2
Bag 3
Bag 1
Bag 2
Bag 3
MDv "
J5 0.3
' S 03
5 03
Sag 1
Bag 2
Bag 3
Methane ' j '
Bag 1
Bag 2
Bag 3
18
13
'3
Mass Correction 1
Bag 1
Bag 2
Sag 3
NG Fuel
Prooerties
COMMENTS:
THC
H/C Ratio
4.000
42.5
71
20.4
HC FID
.0.655
0. 175
0.335
NMHC
H/C Ratio
3.000
13 ' 0.3
'8 0.3
3 ;.3
CO CO2 NOx
1.16 91.6. 0.08
0.03 156.4 0.34
0 25 93.6 0.20
NG CO2 GHV
NG/C Ratio WF BTU/MA3
' 336 0.000 1 009
Bag 1
Bag 2
Baa 3
Mass Corr
Specific
Gravity.
0 555
Bag 1
Sag 2
Bag 3
-------
-------
NATURAL G;
Dyno: 0005 Test No: 922458
Raw Emission
Ambient
Conditions
3aro "Hq Dry Bulb -P.
' J9.44 -5,5
1 Exhaust
HC Ranae Meter
Bag 1
Bag 2
Bag 3
CO
i Bag 1
Bag 2
Sag 3
6 33.2
'4 54.6
16 36.3
Range Meter
19 95.2
'6 3.4
'3 27. 1
C02
Bag 1
Bag 2
3ag 3
-3 :6.3
23 ' 39
23 50.5
VS VEHICLE TEST ANALYSIS
jf "**,
Determination for Concordia
Dew Point -F Spec. Humid.
-3 5 -5.37
i
' Backaround
opm ' Ranae
250.25
42.54
' 7.70
' d
' 6
opm 3ange
475.91
3.25
i 10.25
3
' 6 .
3
nercent
' 3C9 jj
0 363 ! ' _-3
page 2.3;
Processed: 05,27,92 12:54,
Rel. Humid. NOx Corr i
'-~ 39 ? 3795
:.- I
Meter ppm ' HC
~>--3 ' 3.' 7 . . Bag i
J'3 3.13 Bag 2
-'<3 2.32 Bag 3
Meter ppm ' CO
0.5 i.39
?.' , 1.05
0.3 ;.!3
Bag 1
Bag 2
Bag 3
percent CO2
' 5 0.039 Bag 1
' 3 :.037 Bag 2
' 3 :.:37 Bag 3
NOX ' ฐPm ~7f^ ~v
Bag 1
Bag 2
Bag 3
,'5 27.3
'5 43.9
'5 58.4
Bag 1
Bag 2
Sag 3
NMHCe
Bag 1
Bag 2
Bag 3
' 8 42.5
13 7.1
18 20.4
1 129
/ 763
' .' 29
HC Resp Adjust
Bag 1
Bag 2
Bag 3
COMMENTS:
_ >*-' ' L' '! *- ^ 1- A >A IIU.N-M. \
13.71
24.52
29.27
ppm
212.19
35.45
101.85
PPm
.10.68
: 41
2.71
' 5
5
5
-.3 :.;s
0.3 , O.'S
0.3 0.15
18
73
7 3
CH4 Response
/ 129
' '29
ppm ' .
222.88
36.86
, 104.57
0.3 :.50
0.3 1.50
0.3 i.SO
' 48
' 39
!.13'
Bag 1
Bag 2
Bag 3
Methane
Sag 1
Bag 2
Bag 3
Bag 1
Bag 2
Bag 3
aom rue
2.98
. 2.39
2.53
l-HICli .V.MJ FLHL EMISSIONS I.U11JR
Bag 1
Bag 2
Bag 3
\R)RY ! O. ANN \KliOH MIC! !!c; \N
-------
-------
NATURAL GAS
Oyno: 3005 Tost No: 922458 ;
VEHICLE TEST ANALYSIS
MtB 3r*>
page J 3
Processed: OS.'27'92 1C :4
^mission. Mass, and Fuel Economy for Concordia
Natural Gas
-.'ooerties
Natural Gas
Properties
Ovno.CVS
Bag 1
Bag 2
3ag 3
CVS Corrected
Concentrations
Bag 1
Bag 2
Bag 3
: CVS Mass
i Emissions
1 Bag 1
; Bag 2
. Bag 3
Mass Corrections
. Emissions
Bag 1
Bag 2
Bag 3
rotal Mass
Emissions
Bag 1
Bag 2
Bag 3
Mass ,
Emissions '
Bag 1
; Bag 2 i
Bag 3
1 Composite
Emissions
Unrounded
; Rounded
Natural Gas
Fuel Economy
i :s ; ; s; -'ONIM
THC
i H C Ratio
: - ;ooo
NG
i NG/C Ratio
' 3357
VMIX
Jo 44
Ji.'O
CH4C
i pprn
^: 0,91
24.09
' 00.54
CH4
grams
0.53
2 39
4 96
CH4
grams
;.73
: 20
3 33
CH4
grams
i 26
3.09
= 34
CH4
q / mi
3 127
0.800
1.487
CH4
g mi
1 ,471 49
: 471
grams C
per mile
1 41 .749
.c!!-:o .M : HI- i
THC
Density
3.384
i Roll Revs
j 3334
\ 9000
| '5370 -
NMHCc
ppm
9.41
0.1-5
1.72
NMHC
grams
0.44
0.01
0.08
NMHC
grams
0.03
0.00
0.01
NMHC
grams
0.47
0.01
0,09
NMHC
g/mi
0.131
0.003
0.024
NMHC
g/mi
. 0.03540
0.035
grams NG
per grams C
1.336
S- lii'A NAI1ONAL
THC
CWF
. -_,9
NG
CWF
0 749
Miles
3 .500
3.360
3.590
TOTAL HC
opm
220.33
34.24
102.26
TOTAL HC
grams
10.97
2.90
5.03
TOTAL HC
grams
0.76
0 20
0.39 '
TOTAL HC
grams
' 1 .73
'3.10
5 42
TOTAL HC
g/mi
3.258
0.803
1.510
TOTAL HC
g/mi
1 ,50690
1 507
VuHICLLI A.NC
NMHC
H'C Ratio
3 ;occ
Specific
Gravity
: 555
Dilut Factor
COC
opm
474 30
2.29
'09.25
. co
grams
41.35
0.34
. 9.40
CO
grams
-1.16
0.03
3,25
CO
grams
42.51
0.37
3 55
CO
g/mi
: i 807
0.096
2.689
CO
g/mi
3.238
3.2
NMHC
Density
' 698
GHV
BTU/ftA3
'009
Numerator
3.506
C02C
:,275
0.334
'..119
CO2
grams
1 746.38
1938.53
1513.41
CO2
grams
91 .5
'56 4
93.5
C02
grams
'.337.98
2094.93
' 5 0 7 C 1
CO2
g/mi
510.550
542.727
447.636
CO2
g/ m i
509.93
510
UTG BTU's
per gallon
M 41 32
I:L'HL EMISSIONS l.AliORA iCJKY
NMHC CO2
CWF ' WF
, --g '. - --,-
NHV NG
BTU/g Density
47 401 ' 3 ' 53
Dilut Factor Correct
: 0.896
3.101
NOxc
DDm
3.58
24.39
NOX
grams
71
5.21 .
3.32
NOx
grams
0 08
3 34
: 20
NOx
arams
79
5.55
3 32
NOx
g/ m i
0 497
'.438
1 065
NOx
g mi
; .: 401
! ' 4
354554-5
.908225:
3' =====
NG BTU'S NG
per mile MPG
3974 472 ' 2 ""
\NSAKUOk MIC'i'G^N
-------
-------
NATURAL GAS VEHICLE TEST
~
;Dyno: 0005 Test No: 922142
oage i 3
Processed: 05.2892 1455
nput Data for PRACTICE
Bag
Bag 2
Bag 3
Srst- Units
HC FID
0.407
0.124
0-214
-------
-------
i
I
1
rOyrio: D005 Test No: 922142
i
i
Raw
Amoient . Saro 'Ha
Conditions -a
Exhaust
Sag 1 : 0-
Bag 2 -j
Bag 3 , s
. Bag 1 13
Bag 2 rg
: Bag 3 ,3
CO2
Bag 1 j Ts
Bag 2 23
Bag 3 23
NOx
Bag T ' Ts
Bag 2 ? 5
Bag 3 ? 5
Bag 1 H?
Sag 2 ;3
' Bag 3 ; 3
NMHCe (CH4 Response
Bag 1 . ; '23
Bag 2 . ; 63
Bag 3 : ; 33
THC Resp Adjust i
3ag 1
Bag 2
Bag 3
COMMENTS: i
i
NA I UHALUAS VEHICLE TEST ANALYSIS . , ,
>"" ""*>
<- ^^ '"''.
1 ^^^Z * Processed: 0523.92 '455
%^*
A i.l N \,. >.s.3 . _. :. '..M.SS.ONS U-MJORA iQRY :;. >{3 \.N\ \R8OR \.t'C"'t; \s
-------
-------
Dyno: 0005 Test No: 922142
Emission-. Mass, and
Natural Gas
Properties
Natural Gas
Oyno/CVS
Bag 1
Bag 2
: Bag 3
CVS Corrected
Concentrations
: Sag 1
Bag 2
. Bag 3
; CVS Mass
' Emissions
I Bag 1
: Bag 2
i Bag 3
i Mass Corrections
Emissions
Bag 1
Bag 2
I Bag 3
Total Mass
Emissions
Bag 1
Bag 2
Bag 3
Mass
Emissions
Bag 1
; Bag 2
, Bag 3
: Composite
Emissions
Unrounded
Rounded
i Natural Gas
i Fuel Economy
' '" s:s TEST w. \SCON
THC
H'C Ratio
i 0000
NG
NG/C Ratio
VMIX
253 1
4367
. 2530
CH4C
pom
1 57.43
25.07
80.60
CH4
grams
2.15
3.85
CH4
grams
0.43
0.14
0,25
CH4
grams
3.11
2 29
4 10
CH4
g/mi
2.259
0.593
1 .141
CH4
q/mi
1 .08780
1 .088
THC
Density
1 3.884
' ' '
Roll Revs
S3 70
9023
3370
NMHCc
Bem
13.92
0.00
0.48
NMHC
grams
O.S4
c.oo
0.02
NMHC
grams
0.04
0.00
.0.00
NMHC
grams
O.S7
0.00
0.02
NMHC
g/mi
.0.187
0.000
0.006
NMHC
g/mi
0.04048
0.040
o^tmoLfc Ib.SI ANALYSIS
**t\*-
{m}
\ ^o.\ s'ATTn\.M >. r
-Mtcr c \\ r> 'cr
- S.OoO
C02c
: 445
3.955
-.32'
CO2
qrams
'932.34
2:34 39
732
CO2
grams
:05.9
137 4
1C9.5
CO2
grams
2037.94
2371 ~9
'34! "
CO2
DO . 5; '.
512.366
513.023
C02
575. i 3
575
UTG BTU's
per gallon
-41 32
page 3 3
Processed: 05.28/92 14 55
NMHC I C02
CWF i WF
NHV NG
Oi ut Factor rnrr^,
6. ! 93
9 4Q3
6 373
NOxc
3.40
1 31
3 33
NOx
: 33
: 33
0.47
NOx
J.C5
0 02
0.02
NOx
1 08
0 40
0 49
NOx
:.3C2
0 103
0.137
NOx
0.1533
0.15
- o3oc4 . 3
..1 =G1 -^ Z~
- = ;^= ;
ซ
NG BTU's NG
per mile MPG
' 0129.703 ' ' ; '
,NN ARBOR \<:C!I!C; \>
-------
------- |