76-17 AEB
Testing of a Plymouth Lean Burn Vehicle
with an Oxidation Catalyst
April 1976
Technology Assessment and Evaluation Branch
Emission Control Technology Division
Office of Mobile Source Air Pollution Control
Environmental Protection Agency
-------
Background
Lean mixture combustion engines are attractive because of the low
emissions and good fuel economy that are possible with a properly
controlled lean burn engine. The addition of an oxidation catalyst
should allow further improvements in emissions, driveability, and fuel
economy. Chrysler Corporation has conducted research into engine
operation at lean air-fuel ratios and is now planning to market lean
burn vehicles. It also has extensively tested a lean burn vehicle with
an oxidation catalyst.
The Emission Control Technology Division (ECTD) has recently tested
(Report 75-16, 75-23, 76-7) several lean burn vehicles. However, none
of these used a catalyst. Also, only one of the previous vehicles used
systems that would possibly be marketed soon. ECTD, consistent with its
interest in the evaluation of advanced automotive technology, requested
a vehicle for testing. Chrysler Corporation made available a lean burn
vehicle for emissions testing.
The Environmental Protection Agency receives information about many
systems which appear to offer potential for emissions reduction or
improvement in fuel economy compared to conventional engines and vehicles.
EPA's Emission Control Technology Division is interested in evaluating
all such systems, because of the obvious benefits to the Nation from the
identification of systems that can reduce emissions, improve economy, or
both. EPA invites developers of such systems to provide to the EPA
complete technical data on the system's principle of operation, together
with available test data on the system. In those cases in which review
by EPA technical staff suggests that the data available show promise for
the system, attempts are made to schedule tests at the EPA Emissions
Laboratory at Ann Arbor, Michigan. The results of all such tests are
set forth in a series of Technology Assessment and Evaluation Reports,
of which this report is one.
The conclusions drawn from the EPA evaluation tests are of limited
applicability. A complete evaluation of the effectiveness of an emission
control system in achieving improvements on the different types of
vehicles that are in actual use requires a much larger sample of test
vehicles than is economically feasible in the evaluation test projects
conducted by EPA. For promising systems it is necessary that more
extensive test programs be carried out.
The conclusions from this EPA evaluation test can be considered to
be quantitatively valid only for the specific test car used. However,
it is reasonable to extrapolate the results from the EPA test to other
types of vehicles in a directional or qualitative manner, i.e., to
suggest that similar results are likely to be achieved on other types of
vehicles.
-------
Vehicle Description
The vehicle tested was a Plymouth Fury with 360 cubic inch (5899
cc), V-8 engine and a 3-speed automatic transmission. The vehicle was
equipped with a Chrysler lean burn system with an oxidation catalyst.
(The vehicle is described in detail on the following page.)
On this vehicle the lean burn system consisted of an induction
system operating at an air to fuel ratio of about 18 to 1. Spark advance
was electronically controlled. An oxidation catalyst was used for
exhaust after-treatment.
The system used on this vehicle is not necessarily planned for
production vehicles.
Test Procedures
Exhaust emissions tests were conducted according to the 1975
Federal Test Procedure ('75 FTP),, described in the Federal Register of
November 15, 1972 except that no evaporative emissions tests were con-
ducted. Additional tests included the EPA Highway Fuel Economy Test
(HFET), described in the Federal Register, Volume 39, Number 200,
October 15, 1974 and steady state emissions tests.
These tests are conducted on a chassis dynamometer and employ the
Constant Volume Sampling (CVS) procedure, which gives exhaust emissions
of HC, CO, NOx and CO- in grams per mile. Fuel economy is calculated by
the carbon balance method. The fuel used was Indolene unleaded 96 RON
gasoline. All tests were conducted using an inertia weight of 4500
pounds (2041 kg) with a road load setting of 14.0 horsepower (10.4 kW)
at 50 miles per hour (80.5 km/hr).
During these tests the vehicle was tested for sulfate emissions
using the EPA sulfate procedures. A description of the procedure for
measuring sulfate emissions and summary of the test results is given in
the appendix.
Test Results
Exhaust emissions data, summarized below, showed that the Chrysler
test car, using their lean burn system, was well within the levels of
the 1977 Federal emissions standards at high mileage. However, the
vehicle did not meet the statutory 1978 emission standards of .41 gm/mi
HC, 3.4 gm/mi CO, .4 gm/mi NOx. Detailed results appear in the appendix
to this report.
-------
TEST VEHICLE DESCRIPTION
Chassis model year/make1- 1?76 Plymouth Fury
Emission control system - Chrysler,Lean Burn with Oxidation
Engine
type ...... 4,stroke,Y Otto cycle, V-8
bore x stroke .... ... ... . 4;.OQ x 3.58 in./101.6 x 90.9 mm
displacement . .... . . . . . . 360 cu. in./5899 cc
compression ratio . . . . .... 8.4'il-
maximum power @ rpm '. . . . ... 190 hp/142 kW
fuel metering single 4 barrel carburetor
fuel requirement: ....;.... regular unleaded, tested with 96 RON
Indolene unleaded containing .03
Drive Train percent su%r -'
transmission type .....:... 3 speed automatic
final drive ratio . . . . . . . . 2.71:1
Chassis
type t unitized body/frame, front engine^ rear wheel
tire size' !!'.!!!!•'.!!!! GR 78 x 15 drive
curb weight 430° Pounds
inertia weight . 4500 pounds
passenger capacity 6
Emission Control System
basic type ............ lean combustion mixture, electronic
spark advance monolith catalyst
durability accumulated on system . 51,184 miles
-------
'75 FTP Composite Mass Emissions
grams per mile
(grams per kilometre)
Two Tests
1977 Federal Standards
HC
CO
CO
.53 3.97 803
(.33) (2.46) (499)
1.5 15.0
NOx
1.62
(1.01)
2.0
Fuel Economy
(Fuel Consumption)
10.9 miles/gal
(21.5 liters/100 km)
On the EPA Highway Cycle the results were:
EPA Highway Cycle Mass Emissions
grams per mile
(grams per kilometre)
HC
CO
CO,
Average of 2 tests
.28 .44 480
(.17) (.27) (298)
NOx
2.90
(1.80)
Steady state fuel economy results:
Fuel Economy
(Fuel Consumption)
18.4 miles/gal
(12.8 litres/100 km)
Speed mph (km/hr)
15 (24.1)
30 (48.3)
45 (72.4)
60 (96.6)
Fuel Economy
miles/gal
15.5
22.1
21.4
18.9
(Fuel Consumption)
litres/100 km
(15.2)
(10.7)
(11.0)
(12.4)
A comparison of the test vehicle's combined city/highway fuel
economy with that of the 1976 certification Plymouth 360 (as published
in the 1976 Buyer's Guide) showed that the test car had a fuel economy
penalty of 7%. When compared to all vehicles in the same inertia
weight class (4500 Ibs) the test car showed a 15% fuel economy penalty.
City/Highway Combined
Fuel Economy (Fuel Consumption)
miles/gal litres/100 km
Plymouth Lean Burn
(360 CID)
Plymouth 1976 Certification
Vehicle (360 CID)
Average of all 4500 Ib 1976
Vehicles (ave. 350 CID)
13.3
14.3
15.7
(17.7)
(16.5)
(15.0)
-------
In calculating city/highway combined fuel economy, the urban fuel
economy is weighted 55% and the highway fuel economy is weighted 45% to
account for the 55/45 ratio of urban to rural mileage accumulation. The
following equation is used:
MPG , . ,
combined
.55 + .45
MPG , MPG, . .
urban highway
Sulfate emission test results are summarized in the appendix. The
first test sequence showed sulfate levels of 31.2 mgpm over the sulfate
cycle. The test was repeatable with a standard deviation of 4.3 mgpm.
The second test sequence showed sulfate levels of 48.7 mgpm over the
sulfate cycle. The test was repeatable with a standard deviation of 4.5
mgpm. The cause of this increase in sulfate emissions is not known.
These sulfate levels are similar to EPA test results on catalyst vehicles
with excess air.
For comparison, typical vehicle sulfate emission results as found
in the EPA sulfate baseline study are:
Catalyst vehicles with excess air - about 30 mgm/mile H SO
(range 0.3-96)
Catalyst vehicles without excess air - about 17 mgm/mile H_SO,
(range 0.5-83)
3-way catalyst vehicles - 1 mgm/mile HJsO,
Non-catalyst vehicles - 1 mgm/mile H^SO,
The large range in sulfate levels is because the results are for vehicles
using many different technologies and calibrated to different emission
levels.
The vehicle had excellent driveability when it was driven on the
road for a driveability evaluation.
Conclusions
At high mileage this Plymouth Fury equipped with a prototype lean
burn system met the emission levels required by the 1977 Federal standards.
This system had a significant fuel economy penalty relative to
conventional engines tested for 1976 emission standard certification in
the same weight class. EPA has tested other lean burn vehicles meeting
similar emissions levels, several of which had no fuel economy penalty.
Sulfate emission levels were found to be similar to catalyst
vehicles with excess air.
-------
Plymouth Lean Burn System with Oxidation Catalyst
Procedures used to measure sulfate emissions
1. The fuel was drained from the test vehicle. The vehicle was re-
fueled with Indolene HO gasoline containing 0.03% sulfur by weight.
2. The vehicle was prepped by driving the vehicle over one LA-4 cycle
to precondition the vehicle.
3. The following sequence of test cycles was used to measure sulfate
emissions.
a) FTP
b) Sulfate Emissions Test (SET)
c) SET
d) HFET
,e) SET
f) SET
-------
Table A-l
75 FTP Mass Emissions
grams per mile
Bag 1 Cold Transient
Bag 2 Hot Stabilized
Bag 3 Hot Transient
Test Number
77-655
77-756
HC
1.32
1.14
CO
16.27
13.46
CO,
835
822
NOx
2.24
2.72
Fuel
Economy
10.3
10.5
HC
.33
.23
CO
.65
.82
CO 2
833
850
NOx
1.04
1.24
Fuel
Economy
tnpg
10.6
10.4
HC
.52
.44
CO
2.04
1.80
CO,
760
662
NOx
1.70
2.12
Fuel
Economy
11.6
13.3
Table A-2
75 FTP Composite Mass Emissions
grams per mile
Test Number
77-655
77-656
HC
.59
.48
CO
4.25
3.69
C02
813
793
NOx
1.46
1.78
Fuel Economy
10.8
11.1
(mpg)
Table A-3
EPA Highway Cycle Mass Emissions
grams per mile
Test Number
77-642
77-656
HC CO CO2 NOx Fuel Economy (mpg)
.27 .42 479 3.02 18.5
.29 .45 482 ' 2.77 18.3
-------
Table A-4
Steady State Mass Emissions
grains per mile
Test Number
77-757*
77-758
77-759
77-760
77-761
Speed MPH
Idle
15
30
45
60
HC
.05
.69
.85
.18
.17
CO
.06
.34
.21
.25
.43
C00
147
571
399
413
469
NOx
.07
.45
1.46
3.08
4.30
Fuel Economy
.83
15. 5
22.1
21.4
18.9
(MPG)
* grams per minute, gallons per hour.
-------
Table A-5
Test Type HC
75 FTP (composite) .53
Highway . 23
Sulfate (avg.
of 4)
.25
CO
5.37
.61
.73
Sulfate Procedure Emissions
grams per mile
Test Sequence 1
CO2 NOx Fuel Econo.ny (mpg)
791 1.81 11.1
493 3.14 17.9
556
2.87
15.9
35.2
43.0
31.2
Conversion
15.7
30.8
19.8
75 FTP (composite) .49 4,03 772
Highway .26 ,,61 508
Sulfate (avg.
of 4) .27 .62 557
Test Sequence 2
2.28 11.4
2.55 17.4
2.24
15.9
23.9
60.7
48.7
10.9
42.3
31.0
* milligrams per mile
------- |