EPA-AA-TEB-81-4
An Overview
of Several EPA Misfuellng Test Programs
Thomas A. Tupaj
October 1980
Test and Evaluation Branch
Emission Control Technology Division
Motor Vehicle Emission Laboratory
U. S. Environmental Protection Agency
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Abstract
A group of test programs were performed on current passenger cars to assess
the rate of catalyst deterioration due to misfueling with leaded gasoline.
These programs addressed both "casual" misfueling as well as intentional
misfueling. Recovery of the catalyst upon return to unleaded fuel was also
assessed. On the average, one tankful of leaded gasoline was found to triple
hydrocarbon (HC) emissions while causing emissions of carbon monoxide (CO) to
double. Continued use of leaded gasoline in vehicles designed to meet 1980
Federal Emission Standards resulted in HC and CO emissions increasing to
levels which exceeded 1975 Federal Standards. Return to unleaded fuel re-
sulted in recovery of some catalytic activity on slightly poisoned vehicles
although continued use of leaded fuel resulted in a permanent loss of
catalytic activity.
-------
Background
Because there is a price differential between leaded and unleaded gasoline at
the pump, there is a propensity for the consumer to consider using leaded
gasoline in his catalyst equipped vehicle. This propensity is usually a
result of a lack of knowledge on the part of the consumer concerning the true
"costs" involved. These costs include the impact on the environment along
with the fact that the perceived savings in operating costs may not actually
be savings over the useful life of the vehicle.
Apart from the intentional misfueling described above, there are instances of
"casual" misfueling which are a result of gasoline shortages. This type of
misfueling is temporary with the consumer returning to unleaded gasoline when
it becomes available.
This report presents an overview of a number of studies which were designed to
address the environmental impact of fuel switching with respect to exhaust
emissions. Although the operating cost impact is beyond the scope of these
studies, it should be noted that the marginal savings associated with each
fuel purchase is offset by increased maintenance and repair costs, e.g.
decreased oil change intervals, reduced useful life of exhaust systems, and
spark plug fouling with a possible adverse impact on fuel economy, etc.
The environmental impact of fuel switching addressed in these studies has been
limited to the change in regulated exhaust emissions as determined by the 1975
Federal Test Procedure (without evaporative emission test). The emissions of
interest are unburned hydrocarbons (HC), carbon monoxide (CO), and oxides of
nitrogen (NOx). No attempt has been made to assess the increase in elemental
lead in the environment due to increased use of leaded gasoline although this
may also result in costs to society.
A recent study performed for the National Commission on Air Quality (Reference
1)* indicated that price differential may not be the only motivation behind
misfueling. Other reasons cited were better engine performance and better gas
mileage. Motivation notwithstanding, the fact remains that misfueling is
occurring (1,2).
Purpose
The purpose of these test programs was to obtain information that could be
used to adjust the Emission Factor data base. These correction factors would
be needed to calculate the impact on air quality for a given area in the event
that a misfueling rate could be established. Additional tests were performed
on the vehicles in support of Inspection/ Maintenance issues. The purpose of
conducting the additional short cycle tests was to obtain data that could be
used to assess the effectiveness of I/M tests in identifying misfueled ve-
hicles.
*Numbers in parentheses refer to references at end of paper.
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Test Program Design
A number of programs were designed to assess two types of misfueling. These
two types are intentional misfueling and casual misfueling. The first type
addresses the individual who decided to switch to leaded fuel on a regular
basis. This individual .would have modified the tank filler neck restrictor to
allow the use of leaded nozzles. The second type addresses those vehicles
which used leaded fuel only on an emergency basis. This would address those
instances where unleaded gasoline was temporarily unavailable. A summary of
these programs is presented in Table 1.
To obtain information on intentional misfueling, two test programs were imple-
mented. One program, performed by the California Air Resources Board (CARB)
under EPA contract, consisted of controlled mileage accumulation by profes-
sional drivers over a pre-determined course utilizing a controlled fuel
source. A complete description of the program is provided as Attachment A.
While this program provided data concerning deterioration rates for a given
set of conditions, it was realized that consumer-operated vehicles may ex-
perience different deterioration rates due to a random mileage accumulation
and the random lead content of in-use gasolines. Therefore, a second program
was developed to address this problem. This project was performed by
Automotive Testing Laboratories, Inc. (ATL) under another EPA contract. The
test vehicles in this program were part of the "loan vehicle" fleet that was
used in Emission Factor testing at ATL's test facility in St. Louis.
Individuals who brought their personal vehicles to the ATL facility to
participate in the Emission Factors program received a loan vehicle for their
use while their vehicle was being tested. Each participant drove the loan
vehicle for a period of approximately one week. Therefore, each vehicle
received random mileage accumulation due to the driving patterns of the
different drivers. The lead content of the fuel in this program varied
somewhat because the fuel was a mixture of the in-use fuel drained from the
non-catalyst vehicles prior to testing in the Emission Factors program. This
project is described in Attachment B.
The two programs described above provided information on intentional mis-
fueling. It was assumed that the vehicles would experience emission control
deterioration. It was the rate and magnitude which was to be quantified. In
the case of casual misfueling, these two factors were of interest along with
the question of possible rejuvenation of catalytic activity due to a return to
unleaded fuel.
Two test programs were performed to assess casual misfueling. One program was
performed by the California Air Resources Board under EPA contract in con-
junction with the program mentioned previously. This program involved mileage
accumulation on one tankful of leaded gasoline. The vehicles were
subsequently operated on unleaded fuel until HC emissions returned to within
approximately 10% of the original baseline value. The details of this project
are contained in Attachment C. The second program was performed by the EPA at
its Motor Vehicle Emission Laboratory in Ann Arbor, MI. This program was
substantially the same as the CARB test program. However, the vehicles were
operated on a second tankful of leaded fuel after the first rejuvenation
sequence was completed. This secondary poisoning was then followed by a
second rejuvenation series as described in Attachment D. Since some of the
catalyst activity returned after these rejuvenation sequences, an attempt was
made to rejuvenate the grossly poisoned vehicles at the ATL test facility in
St. Louis.
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•Bible 1
Significant Elements of Test Programs
Organization
Calif. Air
Resources
Board
EPA in-house
test program
Calif. Air
Resources
Board
Test
Dates
July 1979
to
October 1979
July 1979
to
September 1979
July 1979
to
October 1979
Type of
Program
Casual
poisoning/
recovery
Casual
poisoning/
recovery
Intentional
poisoning
Automotive
Testing Labs.
(St. Louis, Mo.)
Automotive
Testing Labs.
(TRC, OH)
May 1979
to
December 1979
January 1980
to
June 1980
Intentional
poisoning
Recovery
Number of
Vehicles
10
Types of
Control
Systems
5 Oxidation
Catalysts
5 Oxidation
Catalysts
4 Oxidation
Catalysts
6 Three-Way
Catalysts
4 Oxidation
Catalysts
3 Three-Way
Catalysts
4 Oxidation
Catalysts
3 Three-Way
Catalysts
Lead
Level
2.50 gm/gal.
3.09 gm/gal.
Type of
Mileage
Accumulation
controlled
controlled
2.50 gm/gal. controlled
random random
0.43-1.49 gm/gal.
unleaded
random
Test Cycles Performed
1975 FTP, HFET
1975 FTP, HFET
3-speed idle. Loaded
2-mode
1975 FTP, HFET
Hot 72 FTP. Federal
3-mode, Loaded 2-mode
Two speed idle
1975 FTP, HFET
Federal Short Cycle,
Federal 3-raode, Two
Speed Idle, Raw
Exhaust before and
after catalyst at idle
and 50 mp~h.
1975 FTP, HFET
Federal 3-mode, Two
Speed Idle, Raw
Exhaust before and
-------
All four of the programs described above employed vehicles which were tuned to
manufacturer's specifications. Each vehicle underwent a functional check of
all emission-related components to assure that the systems were operating
correctly. The programs were also designed to assure that all of the vehicles
returned to proper emission control before being returned to their owners.
This was accomplished by rejuvenation where confirmed by testing and by
catalyst replacement where they had been permanently damaged. The vehicles
were operated on unleaded gasoline for a period of time prior to installation
of the new catalyst to assure that lead residue was purged and thereby reduce
the likelihood of future degradation of the emission control system.
Discussion of Results
The data generated from the various test program taken as a whole indicate a
substantial increase in emissions after only one tankful. When compared to
the baseline values, the 27 vehicles exhibited a mean increase for HC of 193%
while for CO the increase was 111% (see Appendix E). The data obtained con-
cerning intentional misfueling (3,4) revealed that the emission levels rose
rapidly for the first tank of fuel and then increased to approach "engine-out"
emissions with continued use of, leaded fuel (Figures 1 and 2). Recovery of
catalytic activity upon return to use of unleaded fuel was observed in some
cases (4,5). The CO emissions of casually poisoned vehicles approached the
original baseline values after a few tankfuls of unleaded gasoline. However,
hydrocarbon emissions remained approximately 10% above the baseline values
even after continued use of unleaded gas. In general, it was observed that
the greater the amount of leaded fuel consumed, the greater the emission
increase and the lower the likelihood of recovery due to subsequent return to
proper fuel. The catalytic activity with respect to HC conversion was the
most affected by the lead poisoning. Oxidation of CO continued but at a lower
efficiency.
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EFFECT OF FUEL SWITCHING ON EXHAUST EMISSIONS
2.71
PVERRGE EMISSIONS
8 VEHICLES
16.8
BASELINE
CflSUflL
INTENTIONAL
ENGINE-OUT
flVERHGE EMISSIONS
8 VEHICLES
0.0
AVERAGE EMISSIONS
8 VEHICLES
Figure 1: Average Emission Levels of Misfueled Vehicles Equipped with Oxidation Catalysts
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EFFECT OF FUEL SWITCHING ON EXHAUST EMISSIONS
21.3
RYERRGE EMISSIONS
9 VEHICLES
RVERRGE EMISSIONS
9 VEHICLES
RVERRGE EMISSIONS
9 VEHICLES
Figure 2: Average Emission Levels of Misfueled Vehicles Equipped with 3-Way Catalysts
-------
While the thrust of these test programs concerned the effect on HC and CO
emissions, the effect on NOx control was also investigated. Nine of the
vehicles tested were equipped with three-way catalyst systems. Two or three
tankfuls of leaded gas were needed to realize an increase in NOx emissions
rather than just one tankful of fuel. Poisoning rate notwithstanding, these
catalysts also exhibited degeneration of emission control due to misfueling.
The end result of misfueling is the destruction of catalytic activity with the
emission levels eventually approaching "engine out" values. Figure 2 de-
scribes the rise in emission levels of these vehicles. The vehicles
represented in this figure were designed to meet 1978 California Emission
Standards (.41 gm/mi HC/9.0 gm/mi CO/1.5 gm/mi NOx). For the purpose of these
tests programs, it was assumed that the same type of systems would be employed
to meet 1980 Federal Standards (.41 gm/mi HC/7.0 gm/mi CO/2.0 gm/mi NOx). The
"engine-out" emissions were obtained by replacing the catalyst with a pipe
equipped with baffles designed to simulate the backpressure caused by the
catalyst.
The test programs were designed to assess HC increases with the testing con-
tinuing until 90% of the "engine-out" values of HC were' reached. The emission
levels of CO and NOx increased during the test program although they did not
increase as rapidly as the HC levels. The programs were restricted by budget
constraints and the ultimate poisoning of the converter with respect to CO and
NOx was never fully achieved. However, the "engine-out" values could be
considered estimates of this total poisoning. It is reasonable to conclude
that continued use of leaded fuel in a vehicle designed to meet 1980 Federal
Emission Standards will result in a regression in emission control to a level
somewhat greater than 1975 Emission Control levels.
The three-way catalyst systems employed an oxygen sensor to allow control of
the air/fuel ratio. From these test programs, it appears that the sensor is
also affected by the use of leaded gasoline (Figure 3). A poisoned oxygen
sensor tends to cause the air/fuel ratio to drift towards a rich setting (6).
The more the sensor is poisoned, the greater the shift towards a rich mixture.
Therefore, not only will the catalyst lose its ability to control the emis-
sions of HC and CO, but the amount of excess HC and CO reaching the catalyst
will increase.
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EFFECT OF MISFUELING ON OXYGEN SENSOR PERFORMRNCE
.0
.5
.0
1.5
HC
ZB
26
2U
22
20
£18
a-10
t-
8
6
tt
2
0
VEH *2 VEH «3
EMISSION
VEH «7
LEVELS
VEH "8 VEH »9
RT SWITCH
CO
1
• 3.0
2.5
£2.0
z
v.
x:
o
"1.5
x
o
0.5
0.0
NOX
VEH «2 VEH «3 VEH «•? VEH «8 VEH «3
EMISSION LEVELS fiT SENSOR SWITCH
i
1
VEH »2 VEH e3 VEH »7 VEH «3 VEH »9
EMISSION LEVELS RT SWITCH
Figure 3: Emission Levels of Oxygen Sensor Equipped Vehicles'
(Five vehicles-CARB test program)
POISONEO SENSOR
NEH SENSOR
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11
Because of the almost instantaneous rise in emissions upon introduction of
leaded fuel it was felt that a fuel effect may be present. This was assessed
by performing emissions tests on both fuels at approximately the same mileage
points. Some tests were performed with the catalyst in place. Others were
performed with the catalysts replaced with a bypass pipe (Table 3). Analysis
of this data (Table 4) reveals a fluctuation of emission levels. However, the
magnitude of this fluctuation reflects test variability (approximately 5%).
It does not reflect the major shift associated with poisoning ( 200% increase
after one tankful). Therefore, the rapid rise in emissions can be attributed
to poisoning.
Table 3
Assessment of Fuel Effect on Emission Control
(gm/mi Determined by 1975 FTP)
Leaded
Vehicle
9401
9402
9403
9404
9405
9406
9407
Odom.
11831
11841
9922
10134
7184
7213
8220
8250
8006
8034
HC
2.85
3.04
1.61
2.06
2.99
2.82
1.54
1.51
1.55
1.52
CO
22.51
12.98
6.92
15.29
36.42
32.97
19.18
20.69
14.52
14.36
NOx
1
1
1
0
1
1
3
3
2
2
.28
.68
.59
.97
.87
.87
.05
.75
.89
.85
Odom.
11909
11946
9943
10199
7241
7269
8280
8309
8062
8090
Unleaded
HC
2.93
3.24
1.68
2.09
2.83
2.82
1.55
1.52
1.79
1.76
CO
9.35
6.26
8.77
13.38
35.07
32.16
20.01
20.24
,18.26
16.47
NOx
1
1
1
0
1
1
3
3
2
2
.29
.57
.44
.86
.66
.83
.70
.71
.65
.67
Comment
At switch
At switch
At switch
At switch
2
Bypass
Bypass
Bypass
Bypass
Bypass
Bypass
Notes:
"At switch" indicates tests with both fuels with no appreciable
mileage accumulation between tests to provide rejuvenation.
"Bypass" indicates "engine-out" emissions due to removal of
catalyst from exhaust system.
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12
Vehicle
Table 4
Percent Change in Emissions Due to Fuel Effect
HC
CO
NOx
9401
9402
9403
9404
9405
9406
9407
Mean
Std. Dev.
2.8
6.6
4.3
1.4
-5.4
0.0
0.6
0.7
15.5
15.8
4.23
6.77
-58.4
-51.7
26.7
-12.5
-3.7
-2.5
4.3
-2.2
25.7
14.7
-5.96
28.9
0.8
-6.5
-9.4
-11.3
-11.2
2.1
21.3
-1.1
-8.3
-6.3
-2.99
9.79
Percent Change = Leaded Value - Unleaded Value
Leaded Value
x 100
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13
The various short cycle tests that were performed in conjunction with the 1975
FTP have not yet been analyzed. The tests that were performed varied from
program to program because the level of interest in any given short cycle
varied during the period of time that these test programs were performed. The
data from these tests are available in the individual reports.
Exhaust pipe skin temperatures before and after the catalyst were measured in
the CARS test programs. The intent of this measurement was to assess the
ability to predict catalyst efficiency by measuring the temperature rise (or
lack of rise) across the catalyst. This assumes that an active catalyst would
generate heat (temperature rise) while an inactive catalyst would radiate heat
(temperature drop). Preliminary analysis revealed substantial data scatter
with no trends immediately evident. Since the basic theory appears sound, the
scatter is probably due to the measurement techniques.
Conclusion
The use of leaded fuel in catalyst equipped vehicles results in increased
emissions. This increase is primarily due to the poisoning of catalytic
material. Three-way catalyst systems experience an additional increase due to
the poisoning of the oxygen sensor. A casually poisoned vehicle will recover
some of its activity. However, the stabilized emission levels of these ve-
hicles will be above the original baseline. The amount of activity lost is
directly related to the amount of leaded fuel used. Continued use of leaded
fuel results in emissions approaching engine-out values with no recovery
evident.
-------
References:
1. "Fuel Switching Analysis", Draft Final Report on Task No. 2 to The Mobile
Source Emission Analysis Contract for the National Commission on Air
Quality, prepared by Energy and Environmental Analysis, Inc.
2. Thomas C. Austin and Mary Eichbauer, "Vehicle Misfueling in California
During 1979", SAE 800397, February 1980
3. "A Study of the Effects of Fuel Switching on Catalyst Equipped Vehicles",
Final Report on Tasks #4 and #7 to EPA Contract #68-03-2693, Automotive
Testing Laboratories, Inc., August 1980.
4. "Catalyst Poisoning and Catalyst Recovery Due to Misfueling", Final
Report on Tasks #2 and #3 to EPA Contract #68-03-2783, California Air
Resources Board, October 1979.
5. James Long, "Casual Misfueling of Catalyst Equipped Vehicles", Report No.
EPA-AA-TAEB-80-1, U.S. Environmental Protection Agency, October 1979.
6. H. U. Gruber and H. M. Wiedenmann, "Three Years Field Experience with the
Lambda-Sensor in Automotive Control Systems, SAE 800017, February 1980.
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Attachment A
Test Program Description
Contract No. 68-03-2783, Task No. 2
Catalyst Poisoning and Catalyst Recovery Due to Misfueling
This test program was performed by the California Air Resources Board at the
Haagen-Smit Laboratory in El Monte, CA. during the period from July 15, 1979
to October 28, 1979. The intent of the program was to assess the rate of
catalyst deterioration due to continual misfueling of the test vehicles. The
gasoline used for this program contained 2.5 gms/gal. of lead. The vehicle
fleet for this program is described below:
Test
Vehicle No.
Description
CID
Odometer
1
2
3
4
5
6
7
8
9
10
1979 Camaro 305
1978 Pinto 140
1978 Pinto 140
1979 Granada 250
1979 Futura 302
1979 Camaro 350
1979 Malibu 231
1979 Sunbird 151
1977 Volvo 242 DL 130
1977 Volvo 242 DL 130
3544
20109
16203
10414
20041
3078
1275
4667
26855
11982
The vehicles utilized in this program reflected the different types of
catalyst systems available at the time of the program. This selection allowed
an assessment of the impact of misfueling on the present in-use fleet of
consumer-owned vehicles as well as a projection of impact on future fleets
with three-way catalyst systems in the vehicle mix. Following is a des-
cription of the catalysts and associated exhaust emission control systems on
the ten test vehicles:
Vehicle t
1
2
Catalyst Type*
OC-Pellet #6498369
TWC-Monolithic #D8EE-
5E212-HA
TWC-Monolithic //D8EE-
5E212-HA
Other Emission Control Systems**
AIR-EGR-EFE
AIR-EGR-OS
AIR-EGR-OS
A-l
-------
A-2
4 OC-Monolithic #D7BE- AIR-EGR
6E212-LA
5 OC-Monolithic #D9BE- AIR-EGR
5E212-JA
6 OC-Pellet #6498369 AIR-EGR
7 TWC-Pellet #6498369 EGR-EFE-OS
8 TWC-Pellet #8998673 EFR-EFE-OS
9 TWC-Monolithic #1219798 FI-OS
10 TWC-Monolithic #1219798 FI-OS
*OC- Oxidation Catalyst
TWC- Three-Way Catalyst
** EFE- Early Fuel Evaporation
AIR- Air Injection Reaction
EGR- Exhaust Gas Recirculation
OS- Oxygen Sensor
FI- Fuel Injection
These ten late model vehicles were procured and tested first in the "as is"
condition (screening test) to see whether they were acceptable, based on their
emission characteristics (high emitter) and mechanical condition (leakage in
the exhaust system), for the test program. They were then equipped with new
catalysts; reconditioned for 500 miles on unleaded fuel and tested on unleaded
fuel. After completion of these baseline tests, the vehicles were operated on
leaded fuel and tested at about 200 mile intervals until the catalyst
efficiency dropped to 25% of the baseline values.
The baseline catalyst efficiency of the fleet vehicles was based on the re-
sults of the 1975 FTP used as a screening test. The subsequent catalyst
efficiency of the individual vehicle was calculated from the results of the
"High Cruise" mode of the Federal Three-mode test.
Final tests were performed with unleaded gasoline to compare with the initial
baseline test data. After the accumulation of 200 miles of operation on
unleaded gasoline to minimize the possible "residue" effect of "lead coating"
on the engine parts of the test vehicles, the poisoned catalysts were replaced
with the original catalysts.
The exhaust emissions of the vehicles were measured over a variety of driving
cycles. The 1975 FTP was performed to compare the emissions to the applicable
standards. A number of short-cycles were performed to provide data on the
feasibility of using these cycles to identify failed catalysts in Inspection/
Maintenance situations. The following sequence details the overall test plan.
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A-3
1. Receive vehicle.
2. Check and adjust to OEM specifications.
3. If test data are acceptable replace OEM catalyst with new catalyst and
precondition the new catalyst with a 500 mile driving schedule consisting
of 45%/55% Highway/City driving miles. Then install probes and measure
exhaust pipe temperatures and raw exhaust emissions upstream and down-
stream of catalyst.
4. Run one 1975 FTP and one Short Cycle Test Sequence (SCTS) to establish
baseline tailpipe exhaust emissions.
5. Replace new catalyst with a bypass pipe which reproduces the backpressure
characteristics.
6. Run one 1975 FTP and one SCTS to establish baseline engine exhaust emis-
sions.
7. Replace bypass with new catalyst.
8. Start the poisoning procedure by fueling with leaded gasoline and running
one 1975 FTP and one SCTS at approximately 200 mile intervals until
catalyst efficiency (based on the high cruise mode of the Federal 3-mode
test) has deteriorated to 25% of the baseline value. For vehicles
equipped with three-way catalyst, oxygen sensors are to be checked and
serviced/replaced as needed.
9. Start fueling with unleaded gasoline.
10. Run one reassessment 1975 FTP test.
11. Replace oxygen sensor with new one and run one 1975 FTP test. If ve-
hicle is not equipped with oxygen sensors, go to step 12.
12. Remove poisoned catalyst.
13. Install bypass and accumulate 200 miles to minimize the effect on emis-
sions of lead residue on engine parts.
14. Run one 1975 FTP and one SCTS test as a final test for baseline engine
exhaust emissions.
15. Replace bypass with OEM catalyst, remove temperature probes and restore
to original condition.
16. Run one final 1975 FTP test to ensure that vehicle meets, exhaust emis-
sions standards.
17. Do necessary repair if needed.
18. Release vehicles or repeat steps 16 through 17 if necessary.
-------
A-4
Mileage accumulation was performed by laboratory technicians. The vehicles
were driven on freeways and city streets near the Haagen-Smit laboratory. A
ratio of 45%/55% Highway/City operation was maintained.
The following figures present the catalyst deterioration of the ten vehicles
as a percent increase from baseline values. The emission values have been
normlized with respect to baseline to allow the display of the various
emissions on one graph.
-------
VEHICLE »1
700
600
500
-------
VEHICLE «3
700
600
zSOO
UJ
SHOO
u.
o
300
FTP HC
FTP CO
FTP NOX
UJ
o
:200
100
17000 172SO 17500 17750
ODOMETER
18000
18250
FIGURE fl-3: CRTRLTST DETERIORflTION
VEHICLE
2000
1800
1600
UJ
"lOOO
o
i- 800
z
UJ
£ 600
UJ
«100
200
NOTE: INCREASE 7.
EXPGGERflTED DUE
TO LOW BASELINE
10900 11100 11300 11500 11700 11900
11000 11200 11400 11600 11800 12000
ODOMETER
FIGURE fi-Ht CRTRLYST DETER IORRTJON
-------
VEHICLE «S
1200
1100
1000
u, 900
2 800
UJ
£ 700
m
u. 600
,_ 500
£ 400
5 300
Q.
200
100
0
NOTE: INCRERSE X
EXRGGERRTEO DUE
TO LOW BASELINE
20600 20700 20800 20900 21000 21100 21200 21300 21400 21500
ODOMETER
UJ
v>
1100
1000
900
I 800
l
700
600
o 500
400
UJ
300
200
100
FIGURE R-5: CflTRLTST DETERIORATION
VEHICLE «6
NOTE: INCRERSE
EXRGGERRTED DUE
TO LOW BRSELINE
3700 3900 4100 4300 4500 4700 4900 5100 5300 5500 5700
OOOHETER
FIGURE R-6: CflTRLTST DETER IORRTI ON
-------
VEHICLE »7
600
500
UJ
:uoo
ui
to
cc
to
300
£200
cc
Ul
100
u
700
600
500
UJ
sUOO
ID
300
UJ
ac200
ui
100
FTP HC
FTP CO
FTP NOX
1300 1400 1500 1600 1700 1BOO 1900 2000 2100 2200 2300 2400
OOOHETER
FIGURE fl-7t CflTflLYST OETERIORflTION
VEHICLE «8
FTP HC
FTP CO
FTP NOX
U800 5000 5200 5400 5600 5800 6000
4900 5100 5300 5500 5700 5900 6100
OOOHETER
FIGURE fl-8t CflTflLYST OETERIORflTION
-------
VEHICLE »9
1200
1100
1000
u, 900
z
2 800
ui
S 700
ai
u. BOO
° 500
£ UOO
£ 300
200
100
0
NOTEi INCRERSE X
EXflGGERflTED DUE
TO LOH BflSELINE
FTP HC
FTP CO
FTP NOX
27250 27500 27750 28000 28250 28500 28750 29000 29*250 29500
ODOHETER
FIGURE A-9i CATALYST OETERIORflTION
VEHICLE »10
900
800
700
tu
^800
UJ
-------
Attachment B
Test Program Description
Contract No. 68-03-2693 Task No. 4 and Task No. 7
A Study of the Effects of Fuel Switching on Catalyst Equippped Vehicles
This test program was performed by Automotive Testing Laboratories. The
initial catalyst deterioration work was performed at their St. Louis
facility while the recovery attempt was performed at their laboratory in
E. Liberty, OH.
Testing was performed on a sample of seven 1979 catalyst-equipped
vehicles as described below. These vehicles were selected from the loan
vehicle fleet utilized in an ongoing Emission Factor Program in St.
Louis. Each vehicle had accumulated between 4,000 and 10,000 miles at
the beginning of the project.
Table 1
Veh. # Make Model CID Catalyst Odometer
9401 Ford Thunderbird 302 Oxidation 8316
9402 Ford Thunderbird 302 Oxidation 9287
9403 Oldsmobile Cutlass 260 Oxidation 6818
9404 Oldsmobile Cutlass 260 Oxidation 7283
9405 Mercury Marquis 351 Three-way 4179
9406 Volvo 245DL 130 Three-way 5795
9407 .Chevrolet Monza 151 Three-way 5182
Upon arrival at the laboratory, each vehicle was examined to ensure that
no extensive modifications had been performed and that the vehicle was
safe to operate. Following a brief driveability evaluation, the vehicles
were placed in soak for a period between 12 and 24 hours.
An underhood inspection was performed prior to the initial as-received
tests. During this examination each vehicle was inspected for
modifications to the emission control system and maladjustments to basic
engine parameters. Disabled and maladjusted components were identified
and repaired at this time. The performance of each component within the
emission control system was also evaluated according to procedures
specified by the manufacturer. Those components found to be
malfunctioning were immediately corrected or replaced. Additionally,
routine tune-up actions we're performed, which included spark plug
replacement, oil change, oil and air filter and PCV valve replacement.
All vehicles were tuned to manufacturer's specifications.
Each vehicle then received three test sequences conducted to determine
the as-received level of emissions and three test sequences with the
catalyst replaced with a bypass pipe that simulated the back pressure of
the catalyst. This latter series of tests determined the emission levels
of the vehicle with a totally ineffective catalyst.
A specific test sequence was performed without modification at designated
intervals during the St. Louis phase of the program. The test sequence
-------
B-2
consisted of a driveability evaluation, engine status and propane
enrichment measurements, a 12 to 24 hour soak, a 1975 Federal Test
Procedure (without evaporative test), a Federal Short Cycle Test, a
Federal Three-Mode Test, and a Two Speed Idle Test. In addition to these
standard tests, the concentrations of HC and CO in the undiluted exhaust
were measured before and after the catalyst at idle and at 50 mph.
A second series of three baseline tests were designed to determine the
emission levels of the vehicle with an ineffective catalyst. For this
series, the catalytic converters were removed from each vehicle and
replaced with a bypass unit. These units were constructed with -baffles
to simulate the average back pressure created by the catalyst.
Following the six baseline test sequences, the vehicles were fueled with
commercially-available leaded fuel (Table 2). The standard gas caps were
replaced with locking models to ensure control of the type of fuel used.
Table 2
Lead Content of Fuel
Date Lead Content (gm/gal)*
9-6-79 0.84
9-10-79 0.75
9-11-79 1.22
9-22-79 .90
10-1-79 1.49
10-2-79 1.32
10-10-79 1.32
10-15-79 1.14
10-23-79 1.16
11-8-79 0.54
11-12-79 0.43
11-19-79 0.45
11-26-79 0.50
12-3-79 1.30
12-10-79 1.25
* The fuel used in this program was drained from vehicles submitted
for test in the Emission Factors Program. This as-received fuel was
analyzed for lead content before being placed in one of two
reservoirs. If supposedly unleaded fuel was found to contain any
lead at all, it was considered "leaded" and was placed in the leaded
fuel reservoir. This resulted in slightly lower lead levels than
anticipated. The values given above were obtained from the analysis
of the reservoir at the intervals indicated.
A series of test sequences were then performed on the seven vehicles at
mileage intervals representing approximately one tankful of fuel. This
progression of testing continued until the catalyst was found to be
"deactivated".
The original work effort provided for a final bypass test sequence and a
test sequence with the new catalyst. The modification to the work effort
which added the rejuvenation test series included a series of bypass and
replacement test sequences. Accordingly, those vehicles that had not
-------
B-3
completed the catalyst deterioration phase of the project at the time of
the work effort modification did not undergo these final deterioration
test sequences.
During January of 1980, all seven vehicles were transported to the East
Liberty, Ohio test facility. In some instances, the deterioration phase
of testing was completed prior to transporting. For those vehicles which
had not completed this phase, deterioration was concluded at the Ohio
location.
The test sequence at the Ohio location was modified to include additional
testing for determination of catalyst efficiency The Federal Short Cycle
Test was eliminated and the raw exhaust was measured before and after the
catalyst during the Federal Three Mode Test and the Two-Speed Idle Test.
Additionally, a pair of thermocouples were installed 1.5 inches upstream
of each catalyst on both sides of the pipe and another pair of
thermocouples were installed 1.5 inches downstream of each catalyst on
both sides of the pipe. Catalyst skin temperatures were recorded for the
steady state conditions during the idle and 50 mph cruise portion of the
test sequence.
Because the vehicles were being tested at a new location, a new baseline
was obtained. The testing program was designed to include misfueling and
rejuvenation effects on the oxygen sensor for the three vehicles equipped
with three-way catalysts. For these three vehicles, a series of baseline
test sequences were performed immediately following the final
deterioration sequence.
The baseline series for three-way catalyst equipped vehicles was:
1. Two test sequences using leaded gasoline, catalyst bypassed, and
original 62 sensor.
2. Two test sequences using unleaded gasoline, catalyst bypassed,
and original 02 sensor.
3. Two test sequences using unleaded gasoline, catalyst bypassed,
and new 02 sensor.
4. One test sequence using unleaded gasoline, original catalyst on,
and new 02 sensor.
5. One test sequence using unleaded gasoline, original catalyst on,
and original 02 sensor.
Four vehicles were equipped with oxidation catalyst only. For these
vehicles, the baseline series consisted of a single test sequence using
unleaded fuel with the original catalyst in place.
Following the baseline tests, all seven vehicles were subjected to
mileage accumulation using unleaded gasoline with test sequences run at
approximately one tankful intervals. For the vehicles equipped with
three-way catalysts, two test sequences were performed at each interval;
one sequence with the original poisoned oxygen sensor installed and one
-------
B-4
with a new oxygen sensor installed. Mileage accumulation was performed
using the poisoned oxygen sensor.
For the vehicles equipped with oxidation catalysts, a single test
sequence, using unleaded gasoline with the original catalyst in place,
was performed.
Mileage accumulation and test sequences for all seven vehicles continued
until at least four full tanks of unleaded gasoline had been consumed.
From the test results, it had been determined that no appreciable
rejuvenation was occurring.
After completion of the mileage accumulation sequences, the four
oxidation catalyst equipped vehicles received a final test sequence using
unleaded gasoline with a new catalyst in place. The three vehicles
equipped with three-way catalysts received a final series of test
sequences consisting of:
1. One test sequence using unleaded gasoline, catalyst bypassed,
and the original C>2 sensor.
2. One test sequence using unleaded gasoline, catalyst bypassed,
and new 02 sensor.
3. One test sequence using unleaded gasoline, new catalyst in
place, and original G£ sensor.
4. One test sequence using unleaded gasoline, new catalyst in
place, and new ©2 sensor. N
The following figures present the catalyst deterioration/recovery of the
seven vehicles as a percent increase from the baseline. The emission
values have been normalized with respect to baseline to allow the display
of the various emissions on one graph.
-------
VEHICLE -9401
500
400
UJ
z
«-»
_J
UJ
cr
OD
U.
e
t-200
o
tc
UJ
100
BEGIN UNLEADED
8300 9300 10300 11300 12300 13300 14300 15300
ODOMETER
FIGURE 8-lt CflTRLYST DETERIORATION/RECOVERY
VEHICLE »9402
400
,300
UJ
en
200
BEGIN UNLEADED
A
9300 10300 11300 12300 13300
ODOMETER
14300 15300
FIGURE B-2; CflTflLTST DETERIORflTION/RECOVERT
-------
VEHICLE *9403
350
300
250
200
150
UJ
= 100
50
UJ
en
BEGIN UNLEADED,
6800 7800 8800 9800 10800 11800 12800 13800
ODOMETER
FIGURE B-3: CflTflLTST DETERIORflTION/RECOVERT
VEHICLE «9H04
300
250
ui
1200
ui
CO
u.150
£100
50
BEGIN UNLERDEO
7200 8200 9200 10200 11200 12200 13200
ODOMETER
FIGURE B-Ut CflTflLYST OETERIORflTION/RECOVERT
-------
VEHICLE -9405
900
800
700
ui
~600
UJ
en
gsoo
£300
0-200
100
FTP HC
= FTP CO
mm. FTP NOX
BEGIN UNLEADED
-v
i _ >*
U100 U600 5100 5600 6100 6600 7100 7600 8100 8600 9100 9600
ODOMETER
FIGURE 8-5: CATALYST DETERIORATION/RECOVERY
VEHICLE «9U06
700
600
zSOO
ui
u.
o
300
UJ
a.
:200
100
FTP HC
FTP CO
it:..,* FTP NOX
BEGIN UNLEADED
5500 6300 7100 7900 8700 9500 10300 11100 11900
5900 6700 7500 8300 9100 9900 10700 11500
ODOMETER
FIGURE B-6: CATALYST DETERIORATION/RECOVERY
-------
VEHICLE -9U07
uoo
350
,300
iu250
CD
u.200
lSO
UJ
o
»JMOO
50
— FTP HC
= FTP CO
,,„=:» FTP NOX
BEGIN UNLEADED
5000 6000 7000 8000 9000 10000 11000
5500 6500 7500 8500 9500 10500 11500
OOOHETER
FIGURE B-7t CflTflLTST OETERIORflTION/RECOVERT
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Attachment C
Test Program Description
Contract No. 68-03-2783 Task No. 3
Catalyst Poisoning and Catalyst Recovery due to Misfueling
This test program was performed by the California Air Resources Board at
the Haagen-Smit Test Laboratory in El Monte, California during the period
of time between July 15, 1979 and October 28, 1979. The intent of this
program was to determine the recovery rate of vehicles equipped with
catalysts that were operated on one tankful of leaded gasoline and
subsequently operated on unleaded gasoline.' The five vehicles which were
chosen for this program were each equipped with oxidation catalysts. The
intent of the program was to assess the effect of casual misfueling of
the existing vehicle fleet. Therefore, 3-way catalysts were not included
in the sample.
Five late model vehicles with odometer readings between 10,000 and 20,000
miles were used in this test program. They were baseline tested on
unleaded fuel and then driven with one full tank of leaded fuel until
fuel gauge read "empty". The lead content of the fuel was 2.5 grams per
gallon. The vehicles were then tested to determine the initial
(poisoning) effects of leaded gasoline on the catalysts. The vehicles
were fueled with unleaded gasoline .thereafter and tested at every
refueling until the catalyst efficiencies had recovered to about 90% of
their respective original values. The catalyst efficiency values were
calculated from the 1975 FTP test results. Restoration work, such as
engine adjustments, oxygen sensor replacement, etc.,. was performed (if
required) before the vehicles were released.
Test Vehicles and Catalysts
The following five vehicles were procured for this project:
Date Test
Received Vehicle No Description CID Odometer
7/18/79 21 1979 Granada 250 15010
7/18/79 22 1979 Fairmont 302 13637
7/17/79 23 1979 Chev.Caprice 305 18454
7/17/79 24 1979 Cordoba 360 10336
7/27/79 25 1979 Chev. Malibu 231 13940
The following is a description of the catalysts used in this program:
Vehicle^ Catalyst Type Other EEC Systems
21 OC-Monolithic #D7BE- AIR-EGR
5E212-LA
22 OC-Monolithic #D9bE- AIR-EGR
5E202-JA
23 OC-Pellet #6498369 AIR-EGR-EFE
24 OC-Monolithic #4004714 AIR-EGR-ESA*
25 OC-Pellet #649836* AIR-EGR-EFE
*Electronic Spark Advance
-------
C-2
Only 1975 FTP tests were performed on the five vehicles. The test
schedule was as follows:
1. Check and adjust to manufacturer's specifications.
2. Run three consecutive 1975 FTP exhaust emissions tests as initial
baseline tests. Omit the third test if the first two are agreeable.
3. Drain tank fuel and fuel with one tankful of leaded gasoline.
4. Accumulate mileage (45%/55% Highway/City) until fuel tank is empty.
5. Fuel with unleaded gasoline and run one 1975 FTP at every refueling.
6. Repeat step 5 until catalyst efficiency has recovered to 90% of its
initial value.
Mileage accumulation was performed by laboratory technicians. The
vehicles, were driven over a set route on freeways and city streets near
the Haagen-Smit Laboratory.
The following figure presents the catalyst deterioration as a percent
increase from baseline values. The normalization allows grouping of all
five vehicles in one figure.
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CRSURL MISFUELING TEST PROGRRM (S VEHICLES)
300
250
CO
cc
oa
£100
so
5 TANKS OF UNLERDEO FUEL
0 200 400 600 800 1000 1200 1400 1600
100 300 500 700 900 1100 1300 1500 1700
TEST MILES
FIGURE C-lt RVERRGE EMISSION INCRERSE CRRB TEST PROGRRM
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Attachment D
Test Program Description
Casual Misfueling of Catalyst Equipped Vehicles
This test program was performed by the Environmental Protection Agency at
the Motor Vehicle Emission Laboratory in Ann Arbor. The intent of this
program was to assess the rate of catalyst recovery after operation of
the vehicle on one tankful of leaded fuel. The program was sub-
sequently modified to perform a second poisoning/recovery series. The
vehicle fleet for this program is described below:
Vehicle Vehicle Model Catalyst
Number Description Year CID Odometer Type
#1 Citation 1980 171 4884 Pellet
#2 Catalina 1978 301 34259 Pellet
#3 Mustang 1979 140 6665 Monolithic
#4 Fury 1978 318 34495 Monolithic
#5 Corona 1979 134 3894 Pellet
The leaded fuel used in this program was Indolene 30. The lead content
of this fuel was 3.09 grams per gallon. Compared to leaded fuel which is
now commercially available, this lead content is quite high. It was
selected for this program because of the uncertainty regarding the effect
of lead exposure on the catalyst and the need for accelerated testing.
The test program consisted of two sequences of misfueling and recovery.
Three 1975 FTPs were conducted on the vehicles as they were received in
order to establish baseline emissions for each. One tank of leaded fuel
was then used to drive one of four established road routes. Two 1975
FTPs were performed still using leaded fuel. One 1975 FTP was conducted
after the fuel was switched to unleaded.
The recovery sequence was comprised of mileage accumulation on three
tanks of unleaded fuel with two 1975 FTPs between each refueling. This
misfueling/recovery cycle was then repeated with slight variations.
After the third tank of Indolene Clear had been consumed and the car
tested, it was refueled with leaded fuel and tested before any further
mileage accumulation. Also, after the tank of leaded fuel and the sub-
sequent FTP were run, the car was refueled with unleaded fuel and tested
prior to the start of the second recovery sequence. The following out-
line provides a detailed explanation of the test program.
Fuel Step
Indolene Clear 1 - Vehicle checkout.
2 - Obtain tailpipe scraping sample to
verify that leaded fuel had not been
previously used in the vehicle.
3 - Fuel vehicle to 40% of tank capacity
with Indolene Clear.
-------
D-2
4 - Precondition with one LA-4 cycle.
5 - 12 to 36 hour soak.
Indolene 30
6 - Cold start 1975 FTP and I/M sequence.
a. I/M Sequence:
Using a garage type analyzer,
record idle HC and idle CO during:
1. Idle
2. 2500 rpm
3. Idle
4. 30 mph/9AHP/1750 IW
5. Idle
7 - Repeat 3-6 twice (total of 3 FTPs).
8 - Fuel vehicle with Indolene 30
Indolene Clear
9 - Run mileage accumulation road route
until 1/8 tank remains.
10 - Take tailpipe scraping sample.
11 - Fill tank with Indolene 30 to determine
the amount of fuel used during mileage
accumulation. Drain tank to 40% level.
12 - Precondition one LA-4 cycle.
13-12-36 hour soak.
14 - Cold start FTP and I/M sequence.
15 - Repeat 11-14 once (total of 2 FTPS).
16 - Fuel vehicle with Indolene Clear
17 - Run mileage accumulation road route
until 1/8 tank remains.
18 - Take tailpipe scraping sample.
19 - Fuel vehicle to 40% of tank capacity
with Indolene Clear.
20 - Precondition one LA-4 cycle.
21 - 12 to 36 hour soak.
-------
D-3
22 - Cold start FTP and I/M sequence.
23 - Repeat 22 to 25 once (total of 2 FTPs).
24 - Fuel vehicle to full tank capacity with
Indolene Clear.
25 - Repeat 17-24.
The following figure presents the deterioration/recovery as a percent
increase from baseline values. This normalization allow the grouping of
four vehicles on one figure. The Plymouth Fury was omitted from this
figure because of the high baseline values of this car. This car
appeared to have operated on leaded fuel previously and it was dropped
from the sample. The tailpipe scrapings revealed a lead level of 11.3%
by weight for the Fury compared to less than 3% by weight for the other
four vehicles.
-------
CflSUflL MISFUELING TEST PROGRflM (5 VEHICLES)
500
1000 1500 2000 2500
TEST MILES flCCUMULBTED
3000 3500
FIGURE 0-1t EPfl IN-HOUSE MISFUELING TEST PROGRAM
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Appendix E
Effect of One Tankful of Leaded Gasoline on Emission Control
1975 FTP (gm/mi)
Baseline 1 Tank
HC_
.43
.53
.40
.36
.56
1.00
2.46
.48
.22
.25
.26
.20
.34
.22
.23
.21
.40
.20
.24
.18
.67
.91
.53
.86
.30
.21
.37
.48
.45 -
co_
3.66
2.73
5.98
2.21
10.50
6.13
17.10
5.70
5.07
1.72
4.10
U95
4.23
1.46
1.35
2.38
4.04
3.56
3.69
2.60
6.79
3.69
3.56
12.45
2.09
2.20
6.56
4.72
3.6
NOx
.82
.67
.98
1.03
.72
1.71
2.24
1.41
1.17
1.53
1.13
.98
.78
1.56
1.18
1.09
.77
.47
.15
.07
1.59
2.04
1.68
1.05
1.03
.76
.71
1.09
.51
GARB Task #3
Veh. #21
Veh. #22
Veh. #23
Veh. #24
Veh. #25
EPA In-House
Veh. #1
Veh. #2*
Veh. #3
Veh. #4
Veh. #5
CARS Task #2
Veh. #1
Veh. #2
Veh. #3
Veh. #4
Veh. #5
Veh. #6
Veh. #7
Veh. #8
Veh. #9
Veh. #10
ATL St. Louis
Veh. #9401
Veh. #9402
Veh. #9403
Veh. #9404
Veh. #9405
Veh. #9406
Veh. #9407
Mean
Std. Dev.
This vehicle was eventually eliminated from the program after determining
that it had been previously operated on leaded fuel.
HC
1.03
1.68
.71
1.02
1.14
3.12
3.97
1.77
.75
1.08
.82
.73
.81
1.69
2.50
1.33
1.17
.74
1.22
1.27
2.55
2.07
1.48
1.78
1.06
.32
.44
1.41
.83
CO
5.29
9.48
7.65
4.67
8.45
9.15
33.05
9.25
15.65
4.01
9.38
5.45
6.24
9.98
9.21
9.27
14.71
8.41
18.57
13.05
19.61
4.52
5.12
14.14
4.78
3.06
7.41
9.98
6.35
NOx
.97
.67
.98
1.02
.75
1.80
2.45
1.88
1.18
1.53
1.02
.92
.78
1.41
.91
1.14
.65
.48
.41
.27
1.82
2.12
1.71
1.12
1.30
.64
.88
1.14
.54
E-l
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