EPA/AA/CTAB/89-03
Technical Report
Durability Testing Of A Toyota LCS-M Carina
by
Gregory K. Piotrowski
June 1989
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 information and to inform the public 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
Emission Control Technology Division
Control Technology and Applications Branch
2565 Plymouth Road
Ann Arbor, Michigan 48105
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UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
ANN ARBOR. MICHIGAN 48105
OFFICE OF
AIR AND RADIATION
..:; 22 :389
MEMORANDUM
SUBJECT: Exemption From Peer and Administrative Review
FROM: Karl H. Hellman, Chief
Control Technology and Applications Branch
Charles L. Gray, Jr., Director
Emission Control Technology Division
The attached report entitled "Durability Testing Of A
Toyota LCS-M Carina," EPA/AA/CTAB/89-03, describes emissions,
fuel economy and oil sample analysis from this MIOO-fueled
vehicle after the accumulation of 6,000 miles driven over the
AMA durability cycle.
Since this report is concerned only with the presentation
of data and its analysis and noes r.ct jp.vclve natters: of polic'-'
or regulations, your concurrence is requested to waive
administrative review according to the policy outlined in your
directive of April 22, 1982.
Concurrence: ^' --<^t,-.>-X; .- <1.•-,**„ Date: -1 ~
Charles L. Gray,"Jr.,. Dir., £CTD
Nonconcurrence : Date :
Charles L. Gray, Jr., Dir., ECTD
cc: E. Burger, ECTD
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Table of Contents
Page
Number
I. Summary 1
II. Background T 2
III. Program Design 4
IV. Test Vehicle Description 5
V. Test Facilities and Analytical Methods 6
VI. Discussion 6
A. Emission Test Results 6
B. Fuel Economy Testing 10
C. Lubricant Analysis 14
VII. Test Highlights 20
VIII.Acknowledgments 20
IX. References 21
APPENDIX A - Description of Driving Cycle A-l
APPENDIX B - Test Vehicle Specifications B-l
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I. Summary
Some industry representatives have stated in private
conversations with EPA personnel that their research suggested
that late-model, catalyst-equipped light-duty methanol vehicles
experience a significant rise in pollutant emission levels
during the' first 5,000-15,000 miles of driving. It was
therefore decided to accumulate approximately 6,000 additional
miles on a methanol-fueled vehicle under carefully controlled
conditions to note any "step-change" behavior in emission
levels.
Accumulation of 6,000 miles over the Durability Driving
Schedule described in Appendix IV of Part 86, 40 CFR Chapter l,
with an MIOO-fueled Toyota LCS-M Carina vehicle has been
completed. Approximately 4,450 miles of driving on a chassis
dynamometer with this vehicle had occurred prior to the start
of this mileage accumulation. The driving was performed under
contract by Automotive Testing Laboratories, Inc. (ATL). The
vehicle was equipped with the same manifold close-coupled
platinum-rhodium catalytic converter before and during this
testing. Toyota provided this catalyst when the car was
delivered to EPA during 1986.
Emissions of hydrocarbons (HC), organic material
hydrocarbon equivalents (OMHCE), methanol (CHjOH), carbon
monoxide (CO) and formaldehyde (HCHO) over the FTP cycle did
not substantially change during this durability testing.
Emission levels of these pollutants at the completion of this
project were similar to emission levels during July 1988,
several months prior to the start of this project.
NOx emissions increased slightly over the first 3,000
miles of this project, from 0.89 to 1.01 grams per mile. NOx
was measured at a higher level of 1.42 grams per mile at the
end of the project. ATL technicians noted a slight misfire at
low-speed cruise conditions during the final 500 miles of
mileage accumulation; this condition was not apparent during
the emissions testing of the vehicle after it was returned to
the EPA laboratory, however. NOx emissions have been measured
at 1.04 grams per mile during FTP testing conducted with this
vehicle since the completion of the work described in this
report, however.
City and highway fuel economies were essentially unchanged
during this project. The gasoline equivalent composite MPG
measured during March 1989, was the same as that measured
during December 1986.
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The oil sample taken after the first 1,500 miles of
project driving showed metal contaminant wear levels twice as
high as samples taken during the remainder of the mileage
accumulation. The first sample was from a 30-weight oil;
approximately 500 chassis dynamometer miles had been
accumulated with this oil in the engine before durability
testing commenced, for a total of almost 2,000 total miles
driven -prior to sampling. The oil was" then changed to a
multi-viscosity formulation; this oil was then sampled and
changed in approximately 1,500-mile increments three times.
II. Background
The subject of variability in emission levels over time
with methanol engine operation was discussed during several
recent meetings between EPA and automotive industry
representatives. Some industry representatives stated that
their research suggested that late model, catalyst-equipped,
light-duty methanol vehicles experienced a significant rise in
overall pollutant emission levels during the first 5,000-15,000
miles of driving. This increase in emissions apparently
occurred in a very noticeable manner; the nature of the
increase was a step-change of considerable magnitude over a
short period of time. These industry representatives did not
specify the magnitude of this step-change, however. Pollutant
emissions were described to be relatively constant before and
after this step-change.
This step-change increase in emission levels had not been
noticed on methanol vehicles tested previously at the EPA
laboratory. Engine-out emission levels were plotted against
odometer mileage during October 1985, for the 1981 MIOO-fueled
Volkswagen Rabbit used as a test vehicle for the ECTD methanol
catalyst test program.[1] The odometer miles over which these
emission levels were tracked was the interval 3,000-15,000
(dynamometer) miles driven. The cycle driven was the FTP cycle.
CO levels declined from approximately 7.5 grams per mile
during the interval 3,100-8,500 odometer miles to 5.4 grams per
mile at 15,000 miles. Engine-out CO then rose steadily,
however, back to 7.5 grams per mile over the FTP currently
(19,000 miles driven). NOx levels were approximately 2.0 grams
per mile at 3,000-7,000 miles; this level dropped off steadily
after 7,000 miles however, and has stabilized at approximately
1.7 grams per mile. HC rose slightly from 1.0 grams per mile
at 3,000 miles to 1.14 grams per mile at 9,000 miles. HC
levels have fallen steadily since then to approximately 0.90
grams per mile currently. HCHO emissions varied from 180 to
560 milligrams per mile during this period of vehicle usage;
HCHO level did not consistently increase or decrease during
that time period, however. The lack of a trend and the
relatively large variations in HCHO emissions over time from
this vehicle have been previously noted.[2]
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This information was concerned with engine-out emission
levels only; a catalyst was not present on the vehicle.
Deterioration of a catalyst through poisoning, overtemping,
etc. could cause a significant increase in emission levels from
a catalyst-equipped vehicle.
Another ECTD-sponsored study looked at emission level
changes_with .catalyst, aging.[3] It was thought -that aging a
catalyst on a methanol-fueled vehicle different than the test
vehicle used for emissions testing would provide useful
information on the emission level increase caused by aging of
the catalyst only.
New samples of two noble metal catalyst configurations,
each at a loading of 20 grams per cubic foot, were emission
tested on a methanol-fueled Toyota Cressida. These catalysts
were then aged approximately 12,000 miles each on a fleet of
methanol-fueled 1983 Ford Escort vehicles. The California
Energy Commission (CEC) was responsible for maintenance of the
Escort fleets and accumulation of the driving miles on the
subject catalysts.
The results from emissions testing over the FTP cycle
after aging were mixed. When tested in a three-way mode,
catalysts with a formula and loading of 3Pt:2Pd(20) showed
virtually no change in emission levels after aging; HC
efficiency actually increased approximately 2 percent with
aging. Pd(20) catalysts uniformly decreased in efficiency with
aging; efficiency decreases ranged from 6 percent for HC to 40
percent for NOx emissions. When tested in an oxidation
catalyst mode, the 3Pt:2Pd(20) catalysts substantially
decreased in HC and CO efficiency after aging. The aged
catalysts had increases in NOx and aldehyde efficiency of 15
and 50 percent respectively, from non-aged catalyst levels,
however. The aged Pd(20) catalysts exhibited increases in HC,
NOx, and aldehyde efficiency over fresh catalyst levels in the
oxidation mode; only CO showed a decrease in catalyst
efficiency with aging.
Several factors may have combined to reduce the usefulness
of this study of catalyst durability on a methanol-fueled
vehicle. First, the catalysts reported here were loaded with
noble metal at 20 grams per cubic foot; our interest at that
time was in a lower cost approach to methanol vehicle
catalysts. Subsequent ECTD testing [4] has suggested that
noble metal catalyst loadings two or three times as large as
those in reference 3 may be necessary in order to reduce
emissions to lower levels. Hence, those catalysts tested may
not be representative of catalyst configurations which may be
placed on future methanol-fueled fleet vehicles. Second,
mileage accumulation on the Escorts was very uneven. Some
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selected cars were signed out almost continuously, while some
were utilized only on those occasions when a great number of
cars were needed. The level of maintenance on those cars also
dropped off appreciably during the test program. The cars were
operated by a number of drivers, on a number of unknown routes,
under a number of different driving conditions, often with
maintenance different from that recommended by _.the
manufacturer. " Therefore, " the mileage "accumulation was
conducted under much less than ideal conditions. Finally, it
was necessary to perform non-routine, unscheduled maintenance
on the Toyota Cressida emissions test vehicle on numerous
occasions during the test program. Several of the services
included replacing the engine fuel injectors. The availability
of a more reliable emissions testing vehicle would have
assisted this program considerably.
It was therefore decided to accumulate approximately 6,000
miles on a methanol-fueled vehicle under more carefully
controlled conditions to note any "step-change" behavior in
emission levels. The vehicle chosen for this work was a Toyota
Carina ecruioped with the Toyota Lean Combustion System Methanol
(T-LCS-M)".
Ill. Program Design
This project involved the accumulation of 6,000 miles on
an MIOO-fueled test vehicle under carefully controlled
conditions in order to note any "step-change" behavior in
emission levels over this time period. The test vehicle was a
methanol-fueled Toyota LCS-M Carina eguipped with a manifold
close-coupled catalytic converter.
The driving was performed under contract by ATL at the
Bendix test track located in South Bend, Indiana. The driving
was conducted during the time period of November 1988 through
March 1989. The 6,000 miles were accumulated on the vehicle in
two 3,000-mile increments. The vehicle was emission tested by
EPA prior to its initial consignment to ATL; upon completion of
the first 3,000-mile increment, the vehicle was returned to the
EPA motor vehicle laboratory and emission tested. The car was
then consigned again to ATL for the second 3,000-mile driving
increment. Upon completion of this work, the vehicle was
returned to EPA for emission testing.
The driving cycle used for this work was the Durability
Driving Schedule described in Appendix IV, Part 86, 40 CFR,
Chapter 1. A description of this driving cycle is given in
Appendix A. All of the driving was conducted on the test
track, rather than on a chassis dynamometer. The engine oil
was changed at 1,500-mile increments and the waste oil was
saved for metals analysis. Results from testing are presented
in the Discussion section.
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IV. Test Vehicle Description
The Toyota Lean Combustion System (T-LCS) was described in
a paper appearing in the Japanese Society of Automotive
Engineering Review (JSAE) for July, 1984.[5] This system made
use of three particular technologies [6] to achieve
improvements in fuel economy as well as to comply with NOx
emission levels under the Japanese 10-mode cycle;
1. A lean mixture sensor [7] was. used in place of an
oxygen sensor to control air/fuel ratio in the. lean mixture
range;
2. A swirl control valve before the intake valve was
adopted to improve combustion by limiting torque fluctuation at
increased air/fuel ratios; [8] and
3. Sequential fuel injection with optimized injection
timing was used to complement the operation of the swirl
control valve.
The Toyota Lean Combustion System Methanol (T-LCS-M) is
similar to the T-LCS, but has been modified to maximize fuel
economy and driving performance while minimizing pollutant
emissions through the use of methanol fuel. SAE Paper 860247
[9] described the development of the T-LCS-M system.
EPA became interested in this system because of its use of
fuel methanol and Toyota provided EPA a T-LCS-M system in a
Carina chassis. The Toyota Carina is a right-hand-drive
vehicle sold in Japan, but currently not exported to the United
States. The power plant is a 1587 cc displacement 4-cylinder,
single-overhead camshaft engine. The engine was modified for
operation on methanol in a lean-burn mode, incorporating the
lean mixture sensor, swirl control valve and timed sequential
fuel injection found on the Toyota lean combustion system.
Modifications to the fuel system included the substitution of
parts resistant to methanol corrosion for stock parts.
Initial testing of this vehicle at the EPA Motor Vehicle
Emissions Laboratory involved the use of both M85 and M100
methanol fuels. This "Phase I" testing involved the
determination and comparison of fuel economy and pollutant
emission profiles of the vehicle when operated on each of these
fuels. A summary of this testing was published in SAE Paper
871090.[10] Testing subsequent to Phase I involved a number of
separate issues concerned with various aspects of the T-LCS-M
system. This testing was conducted using M100 neat methanol
exclusively, and was referred to as "Phase II" testing.[11]
Detailed test vehicle specifications are provided in
Appendix B.
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V. Test Facilities and Analytical Methods
Emissions testing at EPA was conducted on a Clayton Model
ECE-50 double-roll chassis dynamometer, using a direct-drive
variable inertia flywheel unit and road load power control
unit. The Philco Ford constant volume sampler has a nominal
capacity of 350 CFM. Exhaust HC emissions were measured with a
Beckman--Model~ 400 flame ionization detecto'r (FID) . HC test
results in the text are presented without accounting for FID
response to methanol or the difference in HC composition
because of the use of methanol fuel. CO was measured using a
Bendix Model 8501-5CA infrared CO analyzer. NOx emissions were
determined by a Beckman Model 951A chemiluminescent NOx
analyzer.
Exhaust formaldehyde was measured using a dinitrophenyl-
hydrazine (DNPH) technique.[12,13] Exhaust carbonyls including
formaldehyde are reacted with DNPH solution forming hydrazine
derivatives; these derivatives are separated from the DNPH
solution by means of high performance liquid chromatography
(HPLC), and quantization is accomplished by spectrophotometric
analysis of the LC effluent stream.
The procedure developed for methanol sampling and
presently in-use employs water-filled impingers through which
are pumped a sample of the dilute exhaust or evaporative
emissions. The methanol in the sample gas dissolves in water.
After the sampling period is complete, the solution in the
impingers is analyzed using gas chromatograph (GO analysis.[14]
VI. Discussion
A. Emission Test Results
Table 1 and Figures 1 and 2 present FTP emissions results
from the test vehicle at several dates and odometer readings
before the durability testing for comparison. The testing
during October 1988 was conducted prior to the initial
consignment of the vehicle to ATL. The testing during February
1989 was conducted at the 3,000-mile completion point, while
March 1989 denotes testing after completion of the 6,000
durability miles.
Emissions measured as HC over the FTP did not change
markedly from levels measured during December 1986. During the
6,000-mile durability accumulation HC levels remained
essentially constant.
These HC exhaust emissions from an MIOO-fueled vehicle may
be occurring from the engine oil which is incompletely oxidized
in the combustion chambers and catalytic converter. Oil may
enter the combustion chambers as cylinder wall lubrication,
particularly on the compression and exhaust strokes, and from
the crankcase ventilation system.[15,16]
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Table 1
Toyota LCS-M Carina
Emission Test Results, FTP Test Cycle
Approximate
Odometer HC HC* OMHCE* CH30H* CO . NOX- . Aldy.
Date (miles) (q/mi) (q/mi) (q/mi) (q/mi) (q/mi) (q/mi) (mq/mi)
Sep
Dec
Jul
Jul
Oct
Feb
Mar
1986
1986
1987
1988
1988
1989
1989
1570 0.13 0.02 0.18 0.37 0.77 0.55 6.6
1720 0.09 0.01 0.13 0.25 0.74 0.76 11.3
2055 0.08 0.01 0.10 0.19 0.93 1.11 12.1
3850 0.07 0.02 0.09 0.16 1.84 0.73 11.0
4450 0.05 0.01 0.07 0.12 1.00 0.89 9.5
7550 0.06 0.02 0.08 0.14 1.22 1.01 10.2
10800 0.06 0.02 0.08 0.12 0.92 1.42 12.3
Per rulemaking as originally proposed.
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FIGURE 1
TOYOTA LCS-M CARINA
EMISSION RESULTS, FTP CYCLE
I HC (Q/MI) B] OMHCE (Q/MI) ~1 CH3OH (Q/MI) I
0.2
0.15
0.1
0.05
EMISSION LEVELS
2000
4500 7500
ODOMETER MILES
10500
FIGURE 2
TOYOTA LCS-M CARINA
EMISSION RESULTS, FTP CYCLE
I CO (Q/MI)
NOX (Q/MI)
ALOY. (MG/MI)
I
14
12
10
8
6
4
2
0
EMISSION LEVELS
-
-
-
-
-
JH
200
| II • !•
t
mr
•s
-H
i — |
0 4500 7500 10500
ODOMETER MILES
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Emissions of CH^OH and OMHCE also did not vary during
the mileage accumulation work. Methanol was measured directly
during the February and March 1989 testing; prior to this,
methanol emissions were computed with an assumed FID response
factor of 0.75 and an assumed HC ppm to methanol ppm factor
XX/.85, where XX is the fraction of methanol in a methanol/
gasoline blend. It may be interesting to note . that the
calculated CI^OH level of 0.12 grams per mile during October
1988 is the same as the 0.12 grams per mile measured directly
during March 1989.
FTP CO emissions increased to 0.92 grams per mile from
0.77 grams per mile measured during September 1986; however, CO
emissions as high as 1.84 grams per mile were measured during
July 1988. The CO emissions immediately prior to beginning the
durability testing and at the 6,000-mile completion point were
essentially unchanged at approximately 1.0 grams per mile.
These emissions rose to 1.22 grams per mile at the 3,000-mile
point, before falling back to 0.92 grams per mile at the
conclusion of the project; the car did not exhibit any
driveability problems at 3,000 or 6,000 miles. We are not
aware of any reason for this seemingly temporary increase in CO
emissions.
NOx emissions have risen since the vehicle was delivered
to EPA in 1986. The tests in July 1988 were conducted shortly
after the fuel injectors were replaced and a new, slightly
richer air/fuel control strategy was utilized; NOx levels fell
at that time to 0.73 grams per mile, below the current
light-duty vehicle standard. Since then, however, they have
crept steadily upward. At the beginning of the durability
project, NOx was measured at 0.89 grams per mile over the FTP;
NOx levels rose to 1.42 per mile following the completion of
the project.
The vehicle as configured during this project was emission
tested several times over the FTP during May 1989. While other
emission levels did not change substantially during this recent
testing, NOx emissions fell to an average of 1.04 grams per
mile, approximately the same level measured during February
1989. No driveability problems were noted during the May 1989
testing. Engine-out NOx emissions have been measured at
approximately 1.5 grams per mile with an electronic air/fuel
calibration optimized for driveability.[11] A maximum lean
limit air/fuel calibration, however, gave engine-out emission
levels of 1.01 grams per mile for NOx.[11]
The test vehicle is equipped with a manifold close-coupled
catalytic converter. This catalyst, by its location in the
exhaust stream, may be subjected to greater thermal stress than
a catalyst placed in an underfloor location. The increase in
thermal stress may assist catalyst light off, but may reduce
the effectiveness of rhodium for NOx reduction through
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sintering and rhodium diffusion into the alumina support. Wong
and McCabe in an unpublished lecture have attempted to explain
higher temperature oxidation deactivation of rhodium-containing
alumina-supported catalysts.[17] This deactivation may be
occurring with this catalyst system; this would be speculative
on our part, however, as catalyst surface temperature data is
not available.
Formaldehyde levels have remained substantially unchanged
since December 1986 levels. The level of 12.3 milligrams per
mile measured at the end of this mileage accumulation project
is similar to the level of 11.3 milligrams per mile measured in
1986.
HFET cycle emission results are presented in Table 2 and
Figures 3 and 4. Emission levels for September 1986 are not
available as the vehicle was not tested over the HFET cycle at
that time.
Emissions of HC, OMHCE, CH3OH and CO over the HFET have
not changed from December 1986 levels. Figure 2 presents
graphically the change in emission levels for these pollutants
from December 1986 (1,720 miles) to March 1989 (10,800 miles).
The close-coupled manifold converter appears to be very
effective at reducing the level of these emissions.
NOx levels over the HFET appear to increase over time.
NOx roughly doubled from 0.45 grams per mile to 0.97 grams per
mile by July 1987. This level of emissions was maintained
until October 1988, the start of the durability project. At
the end of the 6,000-mile accumulation, however, NOx had risen
to 1.33 grams per mile. This increase is in the same direction
as the increase experienced during the FTP testing. Additional
tests over the HFET since the completion of this project have
not yet been conducted; the recent decrease in NOx emissions
over the FTP mentioned earlier in this report may be relevant
for the HFET cycle also.
Aldehyde emissions over the HFET appear to have decreased
during the mileage accumulation project. The testing conducted
in October 1988, at the start of the project, indicated HCHO
emission levels of 4 milligrams per mile, down substantially
from 8 milligrams per mile measured several months previous.
HCHO emissions were measured at 2.2 milligrams per mile at the
3,000-mile mark (February 1989). HCHO then rose slightly at
the end of the mileage accumulation to 3.7 milligrams per mile;
this level is still substantially below the 8.0 milligrams per
mile measured during July 1988.
B. Fuel Economy Testing
Fuel economy test results are presented in Table 3. City,
highway, and composite methanol MPG figures are presented as
well as gasoline equivalent composite fuel economy. Figure 5
presents graphically city, highway, and composite methanol fuel
economy figures with odometer mileage.
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Table 2
Toyota LCS-M Carina
Emission Test Results, HFET Test Cvcle
Approximate
Odometer HC HC* OMHCE* CH3OH* CO NOx Aldv
Date (miles) (a/mi) (a/mi) (r,/mi\ (r,/mi\ /^,/™;\ /~/_^ , r :.
Dec 1986
Jul 1987
Jul 1988
Oct 1988
Feb 1989
Mar 1989
1720 0.007 0.001 0.010 0.019 0.02 0.45 5.7
2055 0.005 0.001 0.011 0.013 0.04 0.88 10.8
3850 0.010 0.001 0.010 0.013 0.13 0.83 8.0
4450 0.002 0.000 0.005 0.007 0.12 0.74 4.1
7550 0.003 0.000 0.005 0.008 0.05 0.92 2.2
10800 0.005 0.001 0.008 0.014 0.03 1.33 3.7
Per rulemaking as originally proposed.
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FIQURE 3
TOYOTA LCS-M CARINA
EMISSION RESULTS, HFET CYCLE
IHC (Q/Ml)
OMHCE (G/MI)
CH3OH (G/MI)
EMISSION LEVELS
2000
4500 7500
ODOMETER MILES
I
10500
FIGURE 4
TOYOTA LCS-M CARINA
EMISSION RESULTS, HFET CYCLE
CO (Q/MI) B NOX (Q/MI) CH ALDY. (MQ/MI) I
12
10
8
8
4
2
0
EMISSION LEVELS
2000
4500 7500
ODOMETER MILES
10500
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Table 3
Toyota LCS-M Carina
Fuel Economy Test Results
\
Approximate Gasoline
Odometer City Highway Composite Equivalent
Composite MPG
N/A
41.6
39.6
40.8
43.2
42.0
41.6
Date
Sep
Dec
Jul
Jul
Oct
Feb
Mar
1986
1986
1987
1988
1988
1989
1989
(miles)
1570
1720
2055
3850
4450
7550
10800
MPG
18
17
17
18
18
17
18
.7
.9
.0
.2
.6
.9
.0
MPG
N/A
25
24
23
26
26
25
.7
.4
.7
.5
.3
.4
MPG
N/A
20.
19.
20.
21.
20.
20.
7
7
3
5
9
7
FIGURE 5
TOYOTA LCS-M CARINA
METHANOL FUEL ECONOMY
CITY MPQ
30
25
20
MILES PER GALLON
HWY MPQ
COMP. MPQ
15 -
I
10H
5
2000
4000 6000 8000
ODOMETER MILES
10000
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The gasoline equivalent fuel economy values are based on
adjusting for the energy content difference between gasoline
and methanol. The nominal energy content of gasoline has been
established at 18,507 BTU/lb [18] yielding 114,132 BTU/gallon.
Methanol at 8,600 BTU/lb is 56,768 BTU/gallon. The adjustment
for M100 fuel based on fuel energy is:
Gasoline-equivalent adjustment = Energy of gasoline
Energy of methanol
Dividing the energy of gasoline:
Gasoline equivalent adjustment = 2.0105
FTP fuel economy was essentially unchanged by this
project. Methanol MPG was computed to be 18.0 miles per gallon
at project completion; this figure is very similar to the 17.9
miles per gallon measured during December 1986. At the
beginning of the project (October 1988), city MPG was 18.6
miles per gallon; this fuel economy was slightly higher than
both preceding and subsequent measurements, however. The
change in fuel economy measured over the FTP appears to be
negligible when considered over the time period from when the
test vehicle was first loaned to EPA to the end of the mileage
accumulation project.
Fuel economy over the highway cycle has been relatively
steady over time; the 25.7 miles per gallon measured at 10,800
odometer miles is the same level as the 25.7 miles per gallon
measured during December 1986.
C. Lubricant Analysis
Published reports have indicated that the use of methanol
fuel may result in engine wear rates that exceed those of
comparably sized gasoline-fueled engines.[19,20] Typically,
this increased wear is described as having occurred in the top
piston ring and upper cylinder bore area.[21]
Toyota specified an oil change interval of 3,000 miles
when the Carina was delivered to EPA for evaluation. We
requested that the contractor change the oil and filter at a
more conservative 1,500-mile interval during this project. The
used oil was then returned to EPA for metals analysis. Samples
of the oil were sent to the FRAM, Inc. laboratory in
Indianapolis, IN for analysis under the FRAM CODE program.
Table 4 specifies the number of miles accumulated between
oil changes and the viscosity characteristics of the lubricants
used. The oil had been changed shortly prior to the vehicles
initial consignment to ATL; a 30-weight oil specially
formulated for use in methanol engines was added at that time.
As the number of miles driven with this oil was less than 500
at the start of the durability experiment, the vehicle was
consigned with this oil still in the engine. This oil was
sampled after roughly 1,500 miles had been accumulated in the
Durability project, and the sample is referred to as sample 1.
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A multi-viscosity oil, also specially formulated for use
in methanol engines, was provided to ATL for replacement of the
oil at the specified change intervals. Samples of the used oil
are designated as samples 2, 3, and 4 in Table 4. It was
thought that this oil change scheme would allow us to evaluate
both oils under more controlled driving conditions.
Results from testing individual oil ^.samples from _ this
project are presented in Table 5. Four wear metals are
selected for discussion here: iron, aluminum, chromium and
copper. These four are of particular interest because they
relate to major engine components.[22]
Sample 1, the 30-weight oil in the engine at the start of
the program, showed considerably greater metals wear than the
multi-viscosity oil samples. FRAM flagged the iron (Fe),
aluminum (Al), and chromium (Cr) levels from the first sample
as being of particular concern; their standards indicated that
these levels suggested that high engine wear was occurring.
Samole 1 copper (Cu) levels were not unusually high, according
to FRAM.
There may be several reasons for the higher wear metals
observed in sample 1. First, the sample 1 oil was run in the
engine approximately 500 miles longer than the oil in samples
2, 3, and 4; longer periods of engine operation with the same
oil may cause higher levels of wear metals to accumulate. (The
500 miles of driving prior to the initial consignment of the
vehicle to ATL was done on a chassis dynamometer over the FTP
and HFET cycles at 72°F; the vehicle was not cold started below
72°F during this time.) Second, the flow characteristics of
the two oils are quite different; the multi-viscosity oil may
have provided better lubricity during cold start, even at
70°F. Finally, the additive packages in the oils were
substantially different. The oils were formulated by two
different companies; information concerning additive packages,
viscosity range testing, etc., is proprietary to the
manufacturers.
FRAM stated that the levels of Fe and Al in sample 2 were
of moderate concern as wear indicators given our oil change
history. Samples 3 and 4 exhibited Fe and Al levels not high
enough to comment upon, given their wear criteria. Cr levels
were flagged for concern in all samples. The level of Cr in
samples 2, 3 and 4 was described as of moderate concern only.
FRAM indicated that Cr levels should be monitored in the
future, but also suggested that no corrective action need be
taken at the present time. Cu levels were not high enough to
warrant flagging according to FRAM standards.
Pefley in SAE Paper 831704 [22] provides oil analysis wear
metals data from a small fleet of methanol-fueled sedans.
These vehicles were powered by a 1.6-liter vw engines; vehicle
weight and engine displacement were similar to the Toyota
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-16-
Table 4
Toyota LCS-M Carina, Ml00 Fuel
Oil Change Intervals
Sample
Number
l
2
3
4
Odometer
Oil Change
(miles)
3907
5900
7540
9104
10748
Mileage
Between Changes
(miles)
1993
1640
1564
1644
Type Of
Oil Used
30 Weight
Multi-viscosity
Multi-viscosity
Multi-viscosity
Table 5
Toyota LCS-M Carina Durability Project
Metal Contaminants In Individual Samples
Metal
Contaminant
Fe
Al
Cr
Cu
Sample 1
(ppm)
143
40
53
28
Sample 2
(ppm)
61
19
36
7
Sample 3
(ppm)
43
14
26
4
Sample 4
(ppm)
43
13
29
3
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-17-
Carina test vehicle used in this project. The oil used in
Pefley's work was a commercially available SAE 20W-40 SF-CC
oil. The oil was sampled every 1,000 miles and was changed at
3,000-mile intervals. Pefley's vehicles were driven from 7 to
17,000 miles; oil sampling did not occur during the first 3,000
miles of break-in driving. Numerical averages of Pefley's wear
metals data are presented in Figures 6 through 9 together with
sample 1 and average sample 2-4 data from the Carina. durability.
project for rough comparison. Data from a gasoline-fueled
control vehicle from SAE Paper 831704 is also included for
comparison. It must be remembered, however, that the engines
and vehicles from the durability project and those used in SAE
Paper 831704 are different.
The Fe level of 143 ppm from sample 1 is high even
compared to the methanol-fueled vehicle sample average of SAE
Paper 831704. The average Fe levels from samples 2-4 were less
than half of the 115 ppm methanol vehicle level from SAE
831704. The Fe content of the oil from samples 2-4 is roughly
twice as high as the content of the gasoline-fueled control
vehicle from SAE Paper 831704, however.
Aluminum levels measured in samples 2-4 from the current
project were roughly one-third the level measured with the
single-weight oil from sample 1. As in the case of Fe, the
extent of metal contamination with the multi-weight oil used in
this study was much less than the 68 ppm aluminum measured in
the methanol-vehicle oil samples from SAE Paper 831704.
Aluminum in the gasoline-fueled vehicle oil was still less than
the 15 ppm average aluminum level from samples 2-4.
Average chromium levels in methanol-fueled engine oil
samples from both the durability project and the methanol
engine test fleet from SAE Paper 831704 appear to be
substantially higher than the average from the gasoline-fueled
control vehicle. Higher levels of chromium may be related to a
larger amount of chromium found in engine parts designed for
use in methanol-fueled engines.[23,24] Different materials
used in common engine parts would make more difficult even an
indirect comparison such as attempted here. It is interesting
to note, even without the information suggested above as
necessary, that approximately the same degree of Cr
contamination was present in the multi-weight oils used in
samples 2-4 and methanol-fueled engine in SAE Paper 831704.
Cu contamination in samples 2-4 was significantly below
the 13 ppm Cu measured in the gasoline-fueled engine from SAE
Paper 831704. Cu measured in methanol-fueled engine oil from
SAE Paper 831704 was roughly four times the level of the 5 ppm
measured in samples 2-4.
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-18-
FIGURE 6
OIL ANALYSIS - METAL CONTAMINATION
COMPARISON WITH PUBLISHED DATA
IRON (Fe)
PPM BY WEIGHT
GASOLINE- METHANOL- SAMPLE 1*
VEHICLE SAMPLED
SAMPLES 2-4-
•FROM SAE 831704
••DURABILITY EXPERIMENT
FIGURE 7
OIL ANALYSIS - METAL CONTAMINATION
COMPARISON WITH PUBLISHED DATA
ALUMINUM (Al)
PPM BY WEIGHT
GASOLINE- METHANOL- SAMPLE 1-
VEHICLE SAMPLED
•FROM SAE 831704
••DURABILITY EXPERIMENT
SAMPLES 2-4*
-------
FIGURE 8
OIL ANALYSIS - METAL CONTAMINATION
COMPARISON WITH PUBLISHED DATA
I CHROMIUM (Cr)
I
PPM BY WEIGHT
GASOLINE* METHANOL* SAMPLE 1** SAMPLES 2-4"
VEHICLE SAMPLED
•FROM SAE 831704
••DURABILITY EXPERIMENT
FIGURE 9
OIL ANALYSIS - METAL CONTAMINATION
COMPARISON WITH PUBLISHED DATA
I COPPER (Cu)
PPM BY WEIGHT
GASOLINE* METHANOL* SAMPLE 1*
VEHICLE SAMPLED
-FROM SAE 831704
••DURABILITY EXPERIMENT
SAMPLES 2-4-
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-20-
VII. Test Highlights
1. Emissions of HC, OMHCE, CH3OH, CO and HCHO over
the FTP cycle did not substantially change over the 6,000 miles
of durability testing. Emission levels of these pollutants at
the completion of the durability project were similar to
emission levels during July 1989, several months prior to the
start of- this work r
2. NOx levels over both the FTP and HFET cycles
increased substantially during the project. This increase in
NOx emissions may be related to oxidative deactivation of the
rhodium catalyst.
3. City and highway fuel economy was essentially
unchanged by this project; the gasoline-eguivalent composite
MPG measured during March 1989 was the same as that measured
during December 1986.
4. The oil sample taken after the first 1,500 miles of
driving during the project showed metal contaminant levels
twice as high as samples taken during the remainder of the
mileage accumulation. The oil from this first sample was
30-weight oil; approximately 500 chassis dynamometer miles had
been accumulated with this oil in the engine before durability
testing commenced. The oil was then changed to a
multi-viscosity oil; this multi-weight oil was used during the
remainder of this project. The multi-weight oil may have
improved the level of metal wear over that of the single-weight
oil. Differences in driving cycles could have contributed to
this difference in wear level between the two oil types. Each
multi-weight oil sample was taken after approximately
1,550-1,650 miles of driving over the AMA durability cycle.
VIII.Acknowledgments
The Toyota Carina test vehicle was loaned to EPA for use
with alternative fuels research programs by the Toyota Motor
Co., Ltd.
The author appreciates the efforts of Ernestine Bulifant,
Robert Moss, and Stephen Halfyard of the Test and Evaluation
Branch (TEB), Emission Control Technology Division, who
conducted the driving cycle tests and prepared the formaldehyde
and methanol samples for analysis. The author also thanks John
Shelton of TEB who served as Project Officer and intermediary
between ATL and EPA for this project.
The author also appreciates the efforts of Jennifer Criss
and Marilyn Alff of the Control Technology and Applications
Branch, ECTD, for typing, formatting, and editing this report.
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-21-
IX. References
1. "Results of Methanol Catalyst Testing Analyzed For
Trends in Baseline Variance," Memorandum, Piotrowski, G. K.,
OAR/OMS/ECTD/CTAB, October 24, 1985.
2. "Low Mileage Catalyst Evaluation With A
Methanol-Fueled Rabbit - Second Interim Report," Wagner, R. and
L. Landman, EPA/AA/CTAB/84-03, June 1984. '"
3. "Durability of Low Cost Catalysts For
Methanol-Fueled Vehicles," Heavenrich, R. M. , R. I. Bruetsch,
and G. K. Piotrowski, EPA/AA/CTAB/87-01, October 1987.
4. "Catalysts For Methanol Vehicles," Piotrowski, G. K.
and J. D. Murrell, SAE Paper 872052, November 1987.
5. "Development of Toyota Lean Combustion System,"
Kobayashi, N. , et al. , Japan Society of Automotive Engineering
Review, pp. 106-111, July 1984.
6. "NOx Reduction Is Compatible With Fuel Economy
Through Toyota's Lean Combustion System," Kimbara, Y., K.
Shinoda, H. Koide and N. Kobayashi, SAE Paper 851210, October
1985.
7. "Lean Mixture Sensor," Kamo, T., Y. Chujo, T.
Akatsuka, J. Nakano and M. Suzuki, SAE Paper 850380, February
1985.
8. "Effects of Helical Port With Swirl Control Valve On
the Combustion and Performance of S.I. Engine," Matsushita, S.,
T. Inoue, K. Nakanishi, T. Okumura and K. Isogai, SAE Paper
850046, February 1985.
9. "Development of Methanol Lean Burn System," Katoh,
K., Y. Imamura and T. Inoue, SAE Paper 860247, February 1986.
10. "Fuel Economy and Emissions of a Toyota T-LCS-M
Methanol Prototype Vehicle," Piotrowski, G. K. and J. D.
Murrell, SAE Paper 871090, May 1987.
11. "Evaluation of Toyota LCS-M Carina: Phase II,"
Piotrowski, G. K., EPA/AA/CTAB/87-09, December 1987.
12. Formaldehyde Measurement In Vehicle Exhaust At MVEL,
Memorandum, Gilkey, R. L., OAR, QMS, EOD, Ann Arbor, MI, 1981.
13. "Formaldehyde Sampling From Automobile Exhaust: A
Hardware Approach," Pidgeon W., EPA/AA/TEB/88-01, July 1988.
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-22-
IX. References (Cont'd)
14. "Sample Preparation Techniques For Evaluating
Methanol and Formaldehyde Emissions From Methanol-Fueled
Vehicles and Engines," Pidgeon, W. and M. Reed,
EPA/AA/TEB/88-02, September 1988.
15. Automotive Emission Control', 3r~d Edi'tidh, Grouse, W.
H. and D. L. Anglin, McGraw Hill, Inc., New York, NY, 1983.
16. Auto Mechanics Fundamentals, Stockel, M. W. ,
Goodheart-Willcox Company, South Holland, IL, 1982.
17. "Effects of High Temperature Oxidation On the'
Structure and Activity of Rhodium/Alumina and Rhodium/Silica
Catalysts," Wong, C. and R. W. McCabe, Eleventh North American
Meeting of the Catalysis Society, Dearborn, MI, May 1989.
18. Federal Register, Vol. 50, No. 126, page 27179, July
1, 1985.
19. "The Mechanisms Leading to Increased Wear in
Methanol-Fueled SI Engines," T. W. Ryan et al. , SAE Paper
811200, October 1981.
20. "Lubrication Experience in Methanol-Fueled Engines
Under Short-Trip Service Conditions," Chamberlin, W. B. and W.
C. Brandow, SAE Paper 831701, November 1983.
21. "The Effects of Lubricant Composition on SI Engine
Wear With Alcohol Fuels," H. W. Marbach et al. , SAE Paper
831702, November 1983.
22. "Methanol Engine Durability," Ernst, R. J. , Pefley,
R. K., and F. J. Weins, SAE Paper 831704, November 1983.
23. "The Effect of Methanol Substitution on Top Piston
Ring Wear - A Comparative Assessment of Spark Ignited and
Compression Ignited Engines," Nautiyal, P. C. and A. K. Gondal,
SAE'Paper 861589, October 1986.
24. "1.6 Liter Methanol Escort," Ford Motor Company,
Ford Parts and Service Division, Training and Publications
Decartment, 1985.
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A-l
APPENDIX A
DESCRIPTION OF TOYOTA LCS-M TEST VEHICLE
The Durability Driving Schedule for light-duty vehicles
consists of eleven laps of a 3.7-mile course. The basic
vehicle_speed for each lap is given below.
Table A-l
Basic Lap Speed
Durability Driving Schedule
Speed
(miles per hour)
1 40
2 30
3 40
4 40
5 35
6 30
7 35
8 45
9 35
10 55
11 70
Each of the first nine laps contain four steps with
15-second idle periods. These laps also contain five light
decelerations from base speed to 20 miles per hour followed by
light accelerations to the base speed. The tenth lap is run at
a constant speed of 55 miles per hour. The eleventh lap is
begun with wide-open throttle acceleration from stop to 70
miles per hour. A normal deceleration to idle followed by a
second wide-open throttle acceleration occurs at the midpoint
of the lap.
Figure A-l below is a diagram of one lap of the Durability
Driving Schedule taken from 40 CFR, Chapter 1, Part 86,
Appendix IV.
-------
A-2
Figure A-l
Durability Driving Schedule Lap
(From 40 CFR, Chapter 1, Part 86, Appendix IV)
0.7
IlJJE
THEN ACCELERATE
TO LAP SPEED
0 AND 3.7
MILES
3.3
2,9
2.6
'DECELERATE
TO 20 K.P.H.
THEN ACCELERATE
TO LAP SPEED
START-FINISH
STOP
THEN ACCELERATE
TO LAP SPEED
DECELERATE
TO 20 M.P.H.
THEN ACCELERATE
TO LAP SPEED
STOP
THEN ACCELERATE
TO LAP SPEED
DECELERATE
TO 20 M.P.H.
THEN ACCELERATE
.TO LAP SPEED
DECELERATE
TO 20 M.P.H.
THEN ACCELERATE
TO LAP SPEED
DECELERATE
TO 20 M.P.H.
THEN ACCELERATE
TO LAP SPEED
1.3
2.2 STOP
THEN ACCELERATE
TO LAP SPEED
ALL STOPS ARE 15 SECONDS
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B-l
APPENDIX B
DESCRIPTION OF TOYOTA LCS-M TEST VEHICLE
Vehicle weight
Test weight
Transmission
Shift speed code
Fuel
Number of cylinders
Displacement
Camshaft
Compression ratio
Combustion chamber
Fuel Metering
Bore and Stroke
Ignition
Ignition timing
Fuel injectors
2015 Ibs
2250 Ibs
Manual, 5 speed
15-25-40-45 mph
Ml00 neat methanol
Four, in-line
97 cubic inches
Single, overhead camshaft
11.5, flat-head pistons
Wedge shape
Electronic port fuel injection
3.19 inches x, 3.03 inches
Spark ignition; spark plugs
are ND W27ESR-U, gapped at .8
mm, torqued to 13 ft-lb.
With check connecter shorted,
ignition timing should be set
to 10°BTDC at idle. With
check connecter unshorted,
ignition timing advance should
be set to 15°BTDC at idle.
Idle speed is approximately
550-700 rpm.
Main and cold start fuel
injectors capable of high fuel
flow rates. The fuel injector
bodies have been nickel-
plated, and the adjusting
pipes are stainless steel.
-------
B-2
APPENDIX B (CONT'D)
DESCRIPTION OF TOYOTA LCS-M TEST VEHICLE
Fuel pump
Fuel tank
Fuel lines and filter
Catalytic converter
In-tank electric fuel pump
with brushless motor to
prevent corrosion. The body
is nickel plated and its fuel
delivery flow rate capacity
has been increased.
Stainless steel construction;
capacity 14.5 gals.
The tube running from the fuel
tank to the fuel filter has
been nickel plated. The fuel
filter, located in the engine
compartment, has also been
nickel plated. The fuel
delivery rail has been plated
with nickel-phosphorus.
1-liter volume, Pt:Rh loaded,
close coupled to the exhaust
manifold.
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