A7

We would appreciate your review of the foregoing test program.
If you agree with the provisions noted above, please sign a copy
of this letter and send it to me. As soon as all parties have
signed indicating agreement on the program, it will take MBNA
approximately 6-8 weeks to organize vehicle procurement.

“incegrely yours,

farald Poflz, Manager
Emission Control

HP/31

Agreed to:

pil Date: 22

Charles Gray fot ;
Environmental Protection Agency

1
Lit ur — ate: za [77
Tom Cackette, for ON
California Air Resources Board

Sinus —

K.D. Drachand, for
California Air Resources Board



Appendix A

Original Cooperative Agreement Between
EPA, CARB, MBNA and DBAG



Appendix C
Properties of Test Program Fuel and "Title 13" Driving Route



-5-

Upon receipt of the vehicles at MBNA's dealership, MBNA
was allowed to reject a vehicle for any of the following
reasons:

1. Insufficient operating fluid levels,

2. Obvious abuse or misuse of the vehicle evidenced by
vehicle damage or information from maintenance
records,

3. Mileage of vehicle could not be verified,

4. Obvious tampering on the emission control system, or

5. Obvious usage of unauthorized diesel fuel additives

(which was also a pre-selection criterion).

None of the vehicles were rejected by MBNA upon receipt
for any of the above reasons.

Upon acceptance of the vehicle at the dealership, the
vehicle was driven to MBNA's vehicle preparation center. MBNA
recorded essential vehicle information and made checks of the
electrical system, exhaust system, and transmission. The fuel
tank was drained and filled with certification test diesel fuel
and was then driven to the CARB test facilities over the same
route as for "Title 13" testing purposes. "Title 13” is a
California enforcement program designed to check production
line vehicles for compliance with California emissions
standards. A copy of the MBNA fuel properties is included in
Appendix C as well as the "Title 13" road route.

Upon arrival, CARB visually and functionally inspected the
vehicle to assure the integrity of the following items:

Tires

Brakes

Exhaust System

Cooling System

Drive Train

Electrical System

Transmission

Emission Control System (check for obvious tampering)

OAKTRWNHH

If CARB deemed the vehicle safe for testing, as all the
vehicles were, the rear wheels of the vehicle were replaced
with slave tires to prevent the stress of dynamometer testing
on the vehicle owner's tires.

Test Procedure - All ten of the vehicles were tested under
the following federal test procedures:


Appendix B

Vehicle Solicitation Letter Sent by MBNA to Vehicle Owners



Appendix D

Detailed Emissions Test Output from CARB

Due to the large amount of paper associated with the
vehicle tests, the complete results are not included with this
report. If it is necessary to obtain a copy of the complete
results, they are available from EPA. Please phone Thomas
Baines at (313) 668-4366 for further information.


B3

While in the program, your car will be tested on a
vehicle dynamometer at the California Air Resources
Board and MBNA labs. We anticipate that the tests and
measurements will take about 5-10 business days and we
anticipate that less than 250 miles will be added to
your car by the program. All parts and labor required
during these tests will be free of charge to you. You
will only be required to sign an authorization form
permitting representatives of MBNA, EPA and the CARB to
drive and test the car and replace any part deemed
necessary to perform the task of the program.

Please be assured that our technicians will handle your
car with utmost care. Further, Mercedes-Benz of North
America will assume responsibility for the condition of
your car while it is in our custody.

We appreciate your help in conducting this program. If
there are any questions regarding the program, please
contact Mr. Carl Partyka, Los Angeles Zone, Telephone
#213-835-8315. Thank you for your assistance and we
look forward to receiving your questionnaire.

Sincerely,


10.

A5

This procedure should ensure that the fuel system
is properly conditioned with diesel fuel of known
quality prior to emission testing.

EPA and/or CARB personnel are invited to observe these

activities if so desired.

The vehicles will then be driven on the road (same route
as used for Title 13 purposes) by MBNA personnel or their
representatives to the CARB emission test facility and
delivered to EPA/CARB personnel.

Upon delivery the rear wheels of the vehicle will be
replaced with slave wheels and tires to prevent the stress
of dynamometer testing from the customer's tires. Slave
wheels and tires will be supplied by MBNA.

EPA/CARB will perform one routine test sequence
consisting of:

fuel drain and fill
preconditioning cycle
soak

cold FTP 78

HWFET.

If the test results are not voided for test procedure
reasons and the vehicles do not exceed 0.35 g/m PM, the
vehicle will be returned to MBNA personnel. If a test is
void, the test sequence will be finished before a 2nd

test sequence is started. No retesting will be performed
on a vehicle if the only reason for a test failure is that
the vehicle exceeds emission standards for HC, CO, or NOx.

MBNA will have no obligation to adjust and/or repair any
vehicles, even if they failed in one or more emission
constituents. However, it is the intention of DBAG to
bring all vehicles into specification before returning
them to their owners. Records regarding any MBNA actions
in this respect will be available to review by EPA and/or
CARB. -

Vehicles exceeding a PM value of 0.35 g/mi as a result of
a FTP-78 test will be subjected to the following
analytical procedure:

- Test back-pressure in front of TO,

- Check vacuum for EGR and air bypass valve.


-10-

Table 3

Repairs Made to Failing Test Vehicles
-and Back Pressure, EGR Vacuum
and Air Bypass Measurements (bar)

Actions Taken/

Vehicle Repairs Made Back EGR
Number to Vehicle Pressure Vacuum

5

Air
Bypass

- Vehicle driven 0.75 0.30
2-3 miles!

- Vehicle driven 0.65 0.29
3-4 miles!

- Black, thick
oil drained out
of injection pump2
(approx. 3/4 cup)

- Dirty air filter
was cleaned and
reinstalled

- Plug to coolant 0.653 0.273
temperature sensor
was reconnected*

- Vehicle driven 0.804
about 6 milesl-4

On-Road driving consisted of heavy acceleration and

breaking.

Vehicle 6 had only had three oil changes (at 2439, 11978,
and 20825 miles) instead of the seven recommended oil
changes at 1000, 5000, 10000, 15000, 20000, 25000, and
30000 miles.

After second test.

After third test.

0.70

0.753


-7-

An analysis of the test vehicle by DBAG confirmed a
vehicle EGR system malfunction which had been identified by
MBNA during the initial vehicle inspection. This malfunction
was caused by an intermittent contact of a pin in the plug
connecting the coolant temperature sensor to the microprocessor
because the pin was not fully pushed into its socket. (MBNA
feels that this probably occurred during vehicle assembly.)
Without a temperature signal, there is no EGR valve opening and
no EGR flow to the engine. Although this malfunction was noted
by DBAG prior to testing, the agencies (EPA and CARB)
determined that testing would be conducted to determine its
impact.

After the initial testing of vehicle 9, the pin was pushed
into its socket and the connection was found to work properly.
However, with the pin thus repaired, the vehicle was no longer
in the desired "as received" condition. Since it was judged
impractical to try to simulate an intermittent problem, it was
decided to test the vehicle one time with the temperature
sensor connected and one time without the temperature sensor
connected. The emission results so generated would then
represent the range between which the vehicle probably operated
when it had the intermittent pin contact problem.

Vehicle 9 failed the particulate criterion on its second
test with the temperature sensor connected. Vehicle 9 passed
the particulate criterion on the third test with the
temperature sensor disconnected. An attempt was made to
regenerate the trap by driving the vehicle on the road and
vehicle 9 was then tested a fourth time with the temperature
sensor connected.

Experimental Results

Of the 10 vehicles tested, seven vehicles had first-test
particulate results below the 0.35 g/mi criteria level and
three were above the criteria level. Upon trap regeneration
and retesting, two of the three vehicles which initially
exceeded the particulate criteria level, were retested and the
results were below the 0.35 g/mi criteria level. The one
remaining failing vehicle had its trap replaced by DBAG and the
trap was sent to Germany for analysis.

To further break down the same particulate data, three of
the 10 vehicles had first-test results of 0.10 g/mi or less,
six vehicles had first-test results of 0.20 g/mi or less and
nine of the vehicles had first-test results of 0.40 g/mi or
less. All of the particulate data are presented in Table 2.

Of the 10 vehicles tested, two had first-test HC emissions
greater than the 0.46 g/mi HC level to which they were
certified. None of the vehicles had first-test CO or NOx


-6-

1. Fuel drain and fill. A copy of the fuel properties
is included in Appendix Cc.

2. Preconditioning cycle (40 CFR Part 86.132-82 (a)(2))

3. Soak (40 CFR Part 86.132-82 (b)).

4. Cold FTP (40 CFR Part 86.135-82 through 86.137-82).

5. EPA Highway Fuel Economy (40 CFR Part 600 Subpart B).

If the test was not voided for test procedural reasons and
the vehicle's particulate emission rate results did not exceed
0.35 g/mi, the vehicle was returned to MBNA. The 0.35 g/mi
particulate emission rate cut point was specified by DBAG. (If
a vehicle failed to meet HC, CO, or NOx emissions standards, it
was MBNA's intention to repair the vehicle to bring it into
compliance with the certification standards before releasing
the vehicle back to the owner.) If the test was voided for
procedural reasons, the entire test sequence was completed
before a second test sequence was started. Finishing the test
sequence is required to obtain comparable trap oxidizer loading
levels prior to the start of a test sequence.

Vehicles which exceeded 0.35 g/mi PM were to be subjected
to the following analytical procedure:

1. Back pressure in front of the trap oxidizer was
measured.

2. Vacuum for EGR and air bypass valve were checked.

3. Vehicle was driven in an attempt to regenerate the

particulate trap oxidizer.

4, Restorative maintenance activities were carried out
by a DBAG representative if it was believed such
actions would reduce engine out PM.

The vehicle was retested under the same federal test
procedures explained earlier. If the foregoing measures did
not result in lowering the PM emission below 0.35 g/mi, the
trap oxidizer was replaced by DBAG with a new trap oxidizer.
The removed trap oxidizer underwent further analysis by DBAG.

All of the testing followed this predetermined sequence
except for vehicle 9. During the initial testing of this
vehicle, it was observed that the flow rate through the
particulate sampler dropped below the five percent variance
limit specified by the Federal Test Procedure, thus voiding the
test. The testing was finished and the data processed
nevertheless. The unofficial particulate results were 0.41
g/mi, which indicated a problem with the vehicle.


A6

- In case the back-pressure level exceeds the
Service Manual limit of 1.3 bar at 4,000 rpm
(high idle, gear shift lever in "P" position) an
attempt will be made to regenerate the trap by
driving an appropriate cycle on the dynamometer
or highway. In addition, restorative maintenance
activities will be carried out by DBAG if it
believes such actions would reduce engine out PM
emissions.

- If the foregoing measures do not result in the PM
emissions of the vehicle being below 0.35, the TO
will be replaced with a new TO by and at the
expense of DBAG and-sent to DBAG for further
analysis.

11. TOs sent to DBAG for further evaluation will receive one
or more of the following checks as deemed appropriate: ~

- Initial visual inspection,

- Removal of insulation shells and partial
regeneration in an oven at 750 degrees C.

- Alternatively the TO might be installed on an
engine and operated on an engine test stand at
full throttle for 15 min.

- Back pressures will be measured under laboratory
conditions before and after all regeneration
procedures.

- Finally the filter might be cut open to perform
in-depth analysis consisting of:

° Visual examination under a microscope,
X-ray fluorescence spectroscopy,

Qualitative and quantitative analysis with
respect to ashes found in the TO cells,

Mechanical testing of substrate, |

Examination of the structure of welding
seams.

12. A summary cf these findings will be provided to EPA and
CARB.


-9-

levels in excess of the level to which they were certified.
These data are also summarized in Table 2. The complete set of
emission test output from CARB for each vehicle are presented
in Appendix D along with the injection time and-engine idle
speeds which were taken after the emissions test procedure was
completed.

The emission results of the retested vehicles which did
not pass the predetermined cut-off level of 0.35 g/mi
particulate are also contained in Table 2. The particulate
from both vehicles 5 and 6 dropped below the 0.35 g/mi level
upon retesting, however, vehicle 9 remained above 0.35 g/mi.
The particulate from vehicle 5 decreased from 0.38 g/mi to 0.33
g/mi, and the particulate from vehicle 6 decreased from 0.49
g/mi to 0.22 g/mi.

Table 3 is a summary of the repairs which were made to the
three vehicles that exceeded the predetermined cut-off level of
0.35 g/mi particulate. The trap back pressure, EGR vacuum, and
air bypass measurements are also presented in Table 3. The
trap back pressure was taken between the first and second
tests. However, vehicles 5 and 6 were driven about three miles
prior to the trap back pressure test. The short drive, which
consisted of heavy accelerating and braking, is likely to have
affected the condition of the particulate trap oxidizer and
thus the back pressure measurement on vehicles 5 and 6.
Vehicle 6 had thick, black oil in the fuel injection pump. The
oil was drained and was replaced during the subsequent vehicle
operation. (Vehicle 6 had only had three oil changes instead
of the recommended seven oil changes. See Table 3, footnote
2.) The air filter was removed, cleaned and reinstalled on
vehicle 6, also. Based on its service record, DBAG feels that
vehicle 6 is not representative of the vehicle population
utilizing trap oxidizers. It was tested, however, to see what
the effect of such in-use lack-of-maintenance is in terms of
emissions.

Discussion

The objective of this program was to acquire data on trap
durability. In this regard, a few observations can be made.
Of the 10 vehicles tested, there were no gross trap failures,
since none of the vehicles exceeded the California particulate
standard level of 0.4 g/mi except one, and it passed after
maintenance and trap regeneration. Yet such an observation
could mask some underlying problems. The 50,000 mile
certification test results (low mileage plus deterioration)
were 0.12 g/mi particulate for the 300 D and 300 CD and 0.14
g/mi particulate for the 300 TD and 300 SD. Thus, it would be
reasonable to expect that vehicles would emit less than about
0.15 g/mi particulate at the average 36,000 miles at which
these vehicles were tested. Yet on the first test, only five


c2°

3B Laboratory Test Report

PHILLIPS 66 COMPANY

A SUBSIOIARY OF PHILLIPS PETROLEUM COMPANY

BARTLESVILLE. OKLAHOMA 74004

0-2 DIESEL CONTROL FUEL

LOT G-668
EPA Test
Test Results Specification* Method
Cetane Number 45.8. 43-47 |. 0 613
Oistillation Range, OF
18P 353 345-375 0 86
St 407
16 424 400-440
450 p yt
30 470 RECKIVED
40 488
28 504 495-525
522 : 2
70 581 FEB 25 1987
LOS ANGELES
3 78 580-610 EMISSION TEST LABORATO
oP 639
EP 641 630-660
Oxidation Stability, mg/100m1 0.71 1.5 Max.
Gravity, OAPI 35.4 33 - 36 0 287
Total Sulfur, WT% 0.36 0.2-0.4 0 3120
Aromatics (FIA), Vol% 34.2 29 = 35 O 1319
Kinematic Viscosity, cs 2.5 2.2-3.2 0 445
Flash Point (PM, °F) 161 130 Min. 0 93
Particulate Matter, mg/l 1.5 15 Max. 0 2276
Cloud Point, OF +10 15 Max.
Pour Point, °F +5
Corrosion 1 3 Max.
Net Heat of Combustion, -
BTU/1b 19,250
Carbon Density, grams
carbon/gal. 2,778 2750-2806
Cetane Index 46.9 43 - 47

30 ptb of Du Pont FOA #11 antioxidant enhances the stability of this fuel.

*Diesel Fuel as described in Chapter One-Environmental Protection Agency,
subsection 86.113-78, of the Federal Regulations.


EPA-AA-SDSB-88-02

Technical Report

In-Use Performance of Daimler-Benz
Light-Duty Diesel Particulate Trap Oxidizers

By

Thomas M. Baines
and
Philip N. Carlson

February 1988

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.

Standards Development and Support Branch
Emission Control Technology Division
Office of Mobile Sources
Office of Air and Radiation
U. S. Environmental Protection Agency


-12-

Never-the-less, some have considered the particulate
trap-oxidizer system employed by DBAG to be an appropriate
technology for a 0.2 g/mi particulate standard as well. This
is due in part to the fact that the DBAG 50,000 mile
certification particulate results were 0.14 g/mi or less, which
is considerably lower than a 0.2 g/mi standard level. However,
at the test mileage of about 36,000 miles, only 7 of the 10
vehicles had particulate at or below 0.2 g/mi. This indicates
the possibility of excessive in-use deterioration which would
have to be remedied to make this technology usable for a 0.2
g/mi particulate standard.

The above discussion focused on the number of vehicles
whose first-test particulate results were above or below a
certain level and did not differentiate between vehicles of
various maintenance levels, completeness of assembly at
manufacture or other such variables. Thus, the results from
each vehicle were evaluated on a equal basis, or weighting
(i.e., 0.1). This was done because the sample was, with some
constraints, randomly chosen and such a_ sample selection
process is based on the assumption that the resultant data will
be representative of the whole population.

Some would argue that not all of the vehicles are in fact
representative of the whole population at a weighting factor of
0.1, but rather some vehicles (for example, a poorly maintained
vehicle) should have a weighting factor of less than 0.1. EPA
has no data upon which to assign a weighting factor of other
than 0.1, but others may have such data. For their purposes
they may want to assign different weighting factors to the
vehicle data.

MBNA has indicated to EPA that it is MBNA's opinion that
the program was designed to evaluate only the performance of
trap oxidizers and not include concurrent influences such as
improper maintenance or isolated manufacturing defects. This
contrasts with EPA's position that in-use maintenance and
manufacturing variabilities should be included when analyzing
the in-use performance of trap oxidizers. The EPA acknowledges
MBNA's position. The only question from EPA's perspective is
the appropriate weighting factor to be assigned to the
individual data points, as discussed in the previous paragraph.

Conclusions
The following conclusions can be drawn from this project:
- MBNA and DBAG were cooperative and technically
thorough in the vehicle acquisition portion of the
program. :

- CARB's El Monte test facility appeared to do a
_ technically correct job of testing these vehicles.


-11-

vehicles had particulate emissions at such a low level. This
could indicate some level of trap failure.

It has been reported that gasoline-fueled vehicle ceramic
monolith catalysts frequently undergo some level of mechanical
failure. Yet there is sufficient mechanical structure
remaining to give good catalytic activity, even at high
mileages. The same thing may be occurring with these traps.
The traps are made of basically the same material - i.e.,
honeycomb cordierite. The results of this program seem to
point to mechanical failure in that five of the vehicles had
particulate emissions exceeding 0.15 g/mi. This thought is
further bolstered by the results from vehicle 9, which was
tested with and without the temperature sensor connected. With
the temperature sensor connected, the EGR should function
properly, giving lower NOx emissions and higher engine-out
particulate emissions (about 0.55 g/mi for this vehicle
according to MBNA). With the temperature senor disconnected,
the EGR will not function properly, resulting in higher NOx and
lower particulate. In reviewing the data one sees that the
temperature sensor did have the predicted influence on NOx -
i.e., no EGR led to high NOx and visa versa. However, the
trap-out particulate emissions changed in the same direction as
the engine-out particulate emissions. If the trap oxidizer was
mechanically intact, little change in trap-out particulate
emissions should have been seen from a change in engine-out
particulate levels. But since trap-out particulate emissions
did change by an appreciable amount as a function of engine-out
emissions it would indicate some mechanical failure of the trap.

The other observation that can be made about the trap
oxidizer is its usefulness as an aftertreatment device to meet
various emissions standards. The Federal emission standards
are 50,000 mile standards which combine low mileage emission
results with deterioration factors to project a 50,000 mile
emission rate which must be below the standard. The vehicles
which were tested in this program should have had particulate
emissions below the emission standard to which they were
certified, since they had not reached 50,000 miles (with one
exception). Thus, for a 0.4 g/mile particulate standard, all
but one of the vehicles were at or below the standard level.
(One poorly maintained vehicle exceeded the 0.4 g/mi standard
level but was tested below this level after maintenance and
trap regeneration. )

However, the testing took place at about 36,000 miles and
not 50,000 miles. If there is additional deterioration in the
emissions behavior of these vehicles, then by 50,000 miles some
of the vehicles may fail the 0.4 g/mi standard.

The emission control system employed by DBAG for the
Mercedes-Benz vehicles tested was designed specifically for
those vehicles’ engines and for 0.4 g/mi particulate standard.


-8-
Table 2

Vehicle Test Results

Test Vehicle Test Test Odometer Emissions, g/mi HWFET
I.D. Number Number Date (Miles)1} PM HC co CO2_ NOx (MPG)
1 1 4/22 36518 0.24 0.18 2.3 443 0.9 27.2
2 1 4/22 50023 0.08 0.26 1.9 449 0.9 27.4
3 1 4/23 33549 0.10 0.41 1.8 435 0.9 28.6
4 1 4/29 35240 0.18 0.26 2.9 454 0.8 27.0
5 1 4/29 33932 0.38 0.23. =” 1.6 425 0.9 29.6
5 2 S/1 33975 0.33 0.22 1.6 426 0.9 29.7
6 1 4/30 32814 0.49 >» 0.492 6.0 480 0.7 25.2
6 2 5/1 32854 0.22 0.22 1.3 467 1.2 27.3
7 1 5/5 33522 0.09 0.29 2.9 441 0.8 25.8
8 1 5/5 34150 “0.12 > 0.462 4.1 430 0.8 27.7
9 13 5/6 - - - - - - -
9 24 5/8 35602 0.40 0.25 1.6 463 1.0 27.1
9 35 5/12 35640 0.29 0.18 1.1 445 1.7 28.9
9 44 5/13 | 35684 0.40 0.29 , 1.5 453 0.9 27.3
10 1 5/12 36130 0.14 0.26 1.9 451 0.9 26.8
(CA Certification Standards) 0.4 0.46 8.3 - 1.0 -
Mean of All Tests® 0.22. 0.317 2.7 447 0.9 27.2
Standard Deviation® 0.15 0.117 1.4 16 0.1 1.3
1° Mileage at start of test.
2 Exceeded range of measurement.
3 Test voided because the flow rate tolerance was exceeded in bags 1 and 2.
4 Temperature sensor was connected.
5 Temperature sensor was disconnected.
6 The mean and standard deviation are based on only the first valid test of each

vehicle.

The HC values of 0.49 and 0.46 g/mi were used for vehicles 6 and 8, respectively,
in calculating the mean and standard deviation.

_


B2

February 1987

Dear Mercedes-Benz Owner:

Mercedes-Benz of North America is participating in a
joint program with the Environmental Protection Agency
and the California Air Resources Board to obtain
valuable information for engine research and
development, and to help the agencies in evaluating
present and future emission control strategies.

We invite you to participate in this program by filling
out the attached questionnaire at your earliest
convenience and returning it to:

Mercedes-Benz of North America
1 Mercedes Drive
Montvale, N.J. 07645

Attn: Product & Service Engineering

as indicated on the addressed and stamped envelope
enclosed.

The information we receive will be checked against
certain key criteria needed for this program and all
vehicles meeting these requirements will be eligible
for a random drawing determining the participants.

If your vehicle is selected in the random drawing, one
of our local Zone representatives will get in touch
with you to make all necessary arrangements. You will
then bring your car to a local MB dealership, where we
will provide you with a current model year Mércedes-~
Benz loaner car free of charge to you. When you
receive your car back it will be washed and have a full
tank of fuel. In addition, the next scheduled major
service on your vehicle performed at an authorized MB
dealership will also be free of charge.


D2
Table D-1

Injection Time and Engine Idle Speed
of Test Vehicles

Vehicle I.D. Injection Engine Idle
Number Time (degrees) Speed (rpm)
1 23.5 710
2 24.0 720
3 24.0 710
4 24.0 720
5 23.0 700
6 24.0 720
7 24.0 730
8 22.5 720
9 24.5 800
10 24.5 705


Test Vehicle

1985 Mercedes-Benz Light-Duty Diesel Trap Oxidizer

~4-

Table 1

Test Program Vehicle Information

Vehicle Odometer*®

I.D. Number Model VIN Engine Number (miles)
1 300 D 1231331A225300 61795212093728 36444
2 300 D 1231331A251352 61795212103206 49948
3 300 SD 1261251A117247 61795112671387 33462
4 300 D 1231331A229753 61795212095851 35159
5 300 SD 1261201A119072 61795112071582 33849
6 300 D 1231331A257615 61795212106241 32743
7 300 D 1231331A231890 61795212096212 33450
8 300 SD 1261201A138038 61795112071569 34077
9 300 D 1231331A189535 61795212085531 35470
10 300 D 1231331A242239 61795212099776 36056

* Upon check-in at Mercedes-Benz dealership.


A2

‘ERCEDE*

u

February 18, 1987

Mr. Charles Gray

Mobile Source Air Pollution. Control
Environmental Protection Agency
2565 Plymouth Road

Ann Arbor, Michigan 48105

Mr. Tom Cackette

Assistant Executive Officer
California Air Resources Board
P.O. Box 2815

Sacramento, CA 95812

Mr. K. D. Drachand, Chief
Mobile Source Control Division
California Air Resources Board
9528 Telstar Avenue

El Monte, California 91731

Subject: In-Use Testing of Trap Oxidizer Equipped LD
Diesel Vehicles

Gentlemen:

In accordance with recent discussions and correspondence with MBNA
regarding the above referenced test program, we would like to

Propose the following program outline to EPA and CARB:

A. General Program Definitions

1. The test program is a cooperative effort between EPA,

CARB, MBNA and DBAG.

2. Test data derived from this program will not be used
directly as the basis for any emission related recall

activities.

3. ° MBNA will be responsible for vehicle procurement and

shipment to and from the CARB test site.

4. CARB will be fully responsible for the vehicles while

at the CARB test site.


AG

Reasons for rejection are:

- Insufficient operating fluid levels (i.e. engine
oil level above or below maximum/minimum marker
on dipstick),

- Obvious abuse or misuse of vehicle evidenced by
vehicle damage or information from maintenance
records,

- Mileage of vehicle cannot be verified
(i.e. odometer disconnected or replaced).

- Obvious tampering on emission control system
(e.g. removed or disabled emission control
devices, disconnected vacuum lines and/or
electrical connections).

- Obvious usage of unauthorized diesel fuel
additives.

MBNA will keep complete records regarding all vehicles
inspected and the basis for any vehicle being rejected.

EPA and CARB will attempt to return the vehicles to MBNA
at the CARB test facility within five working days after
receipt of the vehicle.

After acceptance of the vehicle by MBNA at its dealer-
ship, it will be driven by MBNA personnel or their
representatives to MBNA's vehicle preparation center
and the following activities will be performed:

- Recording of essential vehicle information
(model type, VIN, engine no., mileage,
maintenance records, etc.),

- Functional check of electrical system
(switches, battery, pre-glow system),

- Visual check of exhaust system for leakages,

- Functional check of transmission >
(i.e. shift points).

- The vehicle tank will be drained and filled
with certification diesel fuel. Fuel samples
from the vehicle tanks will be taken for later
analysis if necessary. In addition, one sample
of the certification fuel will also be taken.


-3-

technology. For example, more information from high mileage
traps is needed in the area of mechanical durability
(especially for relatively brittle materials such as the
ceramic wall flow monolith substrate), catalyst poisoning due
to sulfur or other compounds, ash plugging and other failure
modes. One source of this type of information would be to test
vehicles from a large fleet of trap equipped vehicles such as
production vehicles. However, until recently, no production
vehicles have been equipped with particulate trap oxidizers.
In 1985, Daimler-Benz introduced particulate trap oxidizer
systems on their 300D, 300CD, 300SD and -300TD Mercedes-Benz
vehicles (engine family FMB3.0D9KC20) in the western states
served by the Mercedes-Benz California import facility.

EPA contacted Mercedes-Benz of North America to propose a
cooperative program to assess the in-use performance of
particulate trap oxidizers. The final agreement which resulted
from this proposal included participation from EPA, California
Air Resources Board (CARB), Mercedes-Benz of North America
(MBNA), and Daimler-Benz Aktiengesellschaft (DBAG). In general
terms, MBNA agreed to procure the in-use vehicles on loan from
their owners, CARB agreed to test the vehicles and DBAG agreed
to provide engineering support. A complete copy of the
agreement is contained in Appendix A. The purpose of this
report is to present both the details of this program and the
test results.

Experimental Details

Test Vehicles - The procurement of the vehicles was
performed by MBNA. They acquired a list of all vehicles from
EPA Certification Engine Family FMB3.0D9KC20 (M-B models 300D,
300CD, 300SD and 300TD) for model year 1985 which were sold
from three dealerships (none of which were owned by DBAG or
MBNA) located within 30 miles of the Carson, California MBNA
vehicle preparation center. From this list of 852 vehicles,
every fourth one was selected (a total of 213 vehicles) and a
solicitation letter (a copy of which is in Appendix B) was sent
to the owner. Fifty persons responded as being. willing to
participate in the program. Of these 50, 16 vehicles were
identified as being within the target mileage range of 30,000
to 50,000 miles and as never having used diesel-fuel additives
not authorized by Mercedes-Benz. (The fuel additive selection
criterion was part of the basic program agreement and
compliance with it was determined by reviewing the
questionnaire which accompanied the solicitation letter.) EPA
then randomly ordered the 16 available vehicles for
procurement, from which MBNA procured 10 vehicles. One owner
later refused to participate in this program when contacted by
MBNA and the owner of the eleventh identified vehicle was then
contacted. The vehicle information for the 10 vehicles
included in this program is presented in Table 1.


c3
Table C-1

“Title 13" Vehicle Route Description from
Mercedes-Benz to CARB

Bonita Street N 0.2 miles
223rd Street E 0.8 miles
405 Freeway Ss 3.6 miles
7 Freeway N 3.5 miles
91 Freeway E 5.0 miles
605 Freeway N 15.5 miles
10 Freeway Ww 4.0 miles
Rosemead Blvd. s 0.2 miles
Telstar Ave. E 0.6 miles
Total Mileage 33.4 miles


-2-

In-Use Performance of Daimler-Benz
Light-Duty Diesel Particulate Trap Oxidizers

Abstract

Ten in-use 1985 Mercedes-Benz light-duty diesel vehicles
equipped with particulate trap oxidizer systems and with
mileages between 30,000 and 50,000 miles were tested for
particulate (PM) and gaseous exhaust (HC, CO, C02, and NOx)
emissions. Seven out of ten vehicles had a _ first-test
particulate emission level lower than a predetermined cutoff
point of 0.35 g/mi. (The California PM certification standard
for 1985 light-duty diesel vehicles is 0.4 g/mi.) Attempts
were made to regenerate the particulate trap oxidizers on the
three vehicles which exceeded the 0.35 g/mi PM level and the
vehicles were retested. Two of the three retested vehicles
passed the PM cutoff level. The particulate trap oxidizer was
removed from the vehicle which still exceeded the PM cutoff

level and it was shipped to the vehicle's manufacturer,
Daimler-Benz, for further analysis.*

Introduction

Particulate emissions from light- and heavy-duty diesel
engines are of great interest to EPA for both environmental and
health reasons. Because of the concerns associated with
diesel particulate emissions, EPA has promulgated tighter
particulate standards for light-duty diesel vehicles, and more
recently, for heavy-duty diesel engines. To comply with these
new standards, manufacturers may need to use particulate trap
oxidizers.

Until relatively recently, experience with trap oxidizers
has largely been confined to information from laboratory
testing supplemented by a very limited number of higher mileage
durability programs. This has left an information void with
regards to this important diesel particulate emission control

* MBNA has indicated to EPA that it is MBNA's opinion that
the program was designed to evaluate only the performance
of trap oxidizers and not include concurrent influences
such as improper maintenance or isolated manufacturing
defects. This contrasts with EPA's position that in-use
maintenance and manufacturing variabilities should be
included when analyzing the in-use performance of trap
oxidizers. The EPA acknowledges MBNA's position. The
only question from EPA's perspective is the appropriate
weighting factor to be assigned to the individual data
points, as discussed in the "Discussion" section.


-13-

There appeared to be indication of mechanical

failure in a portion of the traps on the vehicles
tested.

Relative to the 0.4 g/mi particulate standard to
which the vehicles were certified, nine vehicles had
first-test emission results below this level.
However, the tests took place at about 36,000 miles
and if additional trap performance deterioration is
experienced, more vehicles will probably exceed the
0.4 g/mi particulate level if they were to be tested
at 50,000 miles.

The trap system used by DBAG was designed
specifically for the 1985 model year Mercedes-Benz
vehicles and a 0.4 g/mi particulate standard.
Never-the-less, the certification particulate test
results for these vehicles were 0.14 g/mi or less.
The has lead some to conclude that this technology
would be appropriate for a 0.2 g/mi particulate
standard. However, at about 36,000 miles, only 7 of
the 10 vehicles tested had particulate emission
levels at or below 0.2 g/mi. Thus, deterioration of
this emission control system will have to be
controlled to enable it to meet a 0.2 g/mi
particulate standard.


5.

A3

EPA and CARB will be responsible for carrying out the
emissions testing of these’vehicles and will share all
data derived from these tests with MBNA and DBAG.

B. Detailed Program Outline:

1.

The program is designed to sample and test in-use PM
emissions of Daimler-Benz light-duty diesel vehicles
equipped with the Engine Family FMB3.0D9KC20 trap
oxidizer system.

Ten randomly selected vehicles equipped with Engine
Family FMB3.0D9KC20 (MY 85) and a mileage between
30,000 and 50,000 miles will be made available by
MBNA for this purpose.

MBNA will solicit participation of owners for this
program through a mail-out. The customers to whom
the mail-out will be sent will be chosen as follows.
MBNA will identify all purchasers of MY 85 Engine
Family FMB3.0D9KC20 from three dealerships in the
Los Angeles area. After compiling this list ina
random order, MBNA will send a letter to the first
150 customers soliciting their participation and
outlining incentives for participation. MBNA will
offer limited incentives (appropriate loaner cars,
full tank, etc.) to insure a sufficient supply of
appropriate vehicles. Every effort will be made,
however, to acquire the randomly selected vehicles
once identified and in-line with the foregoing
incentives. When positive responses to the MBNA
letter have been received, MBNA will review the
responses in the same order as randomly arranged
originally in an attempt to obtain the 10 test
vehicles. If 10 test vehicles are not obtained from
this first group of letters, additional mail-outs
following this same procedure will be undertaken
until 10 vehicles are available. A complete record
of contacts with customers will be maintained by
MBNA.

To limit the expenses of vehicle procurement, approx.
2-3 vehicles will be scheduled per week. The duration
of the program should not exceed 5 weeks.

The in-use test vehicles will be delivered to MBNA
dealerships by their owners or representatives. Prior
to acceptance of these vehicles they will be visually
inspected by “ENA personnel or their representatives.
Any cars showing obvious mistreatment will,be rejected
at the dealership and will not participate in the test
program.