72-23
EXHAUST EMISSIONS FROM FOUR
GENERAL MOTORS LOW EMISSION
. PROTOTYPE VEHICLES
April 1972
Henry L. Gompf
Test and Evaluation Branch
Environmental Protection Agency
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Background
The General Motors Corporation supplied four low emission
prototype vehicles to the Office of Air Programs for evaluation.
The test vehicles were desired to demonstrate possible 1975-76
emission control systems and to compare emissions measured by
the 1972 and 1975 Federal Emission Test Procedures. Testing of
each vehicle at both the GM and EPA laboratories enabled compar-
ison of low emission test capabilities.
Vehicles Tested '
The following is a brief description of each of the vehicles
tested:
Vehicle #61420
The test vehicle was an Oldsmobile 88 equipped with a
455 CID engine and automatic transmission. The vehicle was
equipped with exhaust gas recirculation, an oxidizing catalytic
reactor and air pump. The fuel specified was Indolene Clear
(lead free) .
Vehicle #61421
An Oldsmobile 88 with a 455 CID engine and automatic
transmission was equipped with exhaust gas recirculation, dual
bed oxidizing-reducing catalytic reactor and an air pump. Test
fuel was Indolene Clear (lead free).
Vehicle #60418
A 455 CID Oldsmobile 88 with an automatic transmission was
converted to run on LPG fuel. The vehicle was equipped with
exhuast gas recirculation, two oxidizing catalysts and an air
valve to add oxidizing air to the catalysts.
Vehicle #62115
A Buick Gran Sport with 455 CID engine and automatic
transmission was equipped with a modified intake manifold to
facilitate early fuel evaporation. In addition exhaust gas
recirculation, exidizing catalyst and air pump systems were em-
ployed. Test fuel was Indolene Clear (lead free).
Test Program
All testing was performea in accordance with. the July 2, 1971.
Federal Register. This procedure will be used for the certi.ficatio
of 1975 model year light duty vehicles.
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Test Results
The full series of tests run by GM and EPA are presented
in the Appendix of this report. Vehicle #61421 with the dual
bed reactor showed the lowest overall emissions meeting the 1976
emission levels in one test of four.
Vehicle #60418 and #61420 consistentaly achieved the
emission levels required for 1975 both having somewhat too
high oxides of nitrogen emissions to meet the 1976 requirements.
Conclusions
While three of the vehicles tested demonstrated emission
levels approaching those required for 1975 with one of these
achieving 1976 levels in one test, these are experimental
vehicles with no definitive measure of the durability capabil-
ities of the system. The emission levels measured at the EPA
laboratory are generally in good agreement with those measured
by General Motors.
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Testing at GM
3/15/72
3/17/72
Testing at EPA
3/22/72
3/24/72
Testing at GM
3/30/72
4/4/72 '
Vehicle #62115 Early Evaporative Manifold
Oxidizing Cats.lyst 455 CID
EGR
Buick GS
A.I.'R.
HC CO CO?
NOx
1972
1.09
1.02
.91
1.29
1.08
1.04
1975
0.70
0.72
0.61
0.83
0.73
0.69
Normal
1972 1975
4.71
.4.16
""'
2.46
.•2.20
-;
Long Path
1972 1975
4.05
4.19
4.93
4.38
4.90
4.90
2.06
2.30
2.74
2.42
2.90
2.52
1972
.""
870.1
820.2
1975
...
331.9
781.9
1972
1.23
1.05
1.12
1.18
1.14
0.91
1975
1.17
1.02
1.07
1.12
1.12
0.86
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Testing at GM
2/8/72
2/18/72
Testing at EPA
2/23/72
2/24/72
2/26/72
2/29/72
Testing at GM
3/4/72
3/6/72
Vehicle#61421 Dual Bed Catalyst
EGR
Oldsmobile 88
Programmed A.I.R.
HC CO
455 CID
CO 2
NOx
1972
0.49
0.56
0.66
0.73
0.66
0.63
0.48
0.59
1975
0.31
0.36
0.41
0.43
0.38
0.37
0.34
0.38
Normal
1972 1975
6.19
8.84
6.26
4.24
5.29
.5.33
3.08
2.16
..'
Long Path
1972 1975
2.41
5.34
6.25
6.26
4.86
5.44
1.68
2.72
5.35
3.10
3.70
2.78
1972
1025.1
1023.1
1008.8
942.3
1975
979.7
981.7
972.7
899.3
1972
0.46
0.53
0.66
0.57
0.56
0.4^
0/60
0.57
1975
0.38
0.43
0.54
0.48
0.48
0.37
0.48
0.46
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Vehicle #61420
Testing at GM
2/16/72
2/18/72
Testing at EPA
2/23/72
2/24/72
2/26/72
2/28/72
2/29/72
Testing at GM
3/6/72
3/10/72
HC
Oxidizing Cata!.yst
EGR
Oldsmobile. 88
A.I.R.
CO
455 CID
CO?
NOx
1972
0.38
0.43
0.29
0.26
0.31
0.40
0.27
0.36
. 0.35
1975
0.27
0.27
0.20
0.17
0.18
0.26
0.17
0.25
0.26
Normal
1972 1975
6.16
5.52
5.32
5.70
8.14
3.62
2.83
3.08
4.03
4.54
Long Path
1972 1975
7.21
5.72
6.20
5.57
5.28
5.80
8.18
6.17
4.48
3.87
3.23
3.70
3.04
3.12
4.13
4.67
2.94
2.17
«•'
1972
952.0
937.0
938.0
918.9
956.0
1975
904.3
"889.1
892.2
876.3
911.0
1972
1.08
1.05
1.14 '
1.07
1.11
1.06
1.16
1.00
1.18
1975
1.10
1.09
1.16
1.09
1.11
1.08
1..18
1.01
1.18
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Vehicle #60418
Testing at GM
2/29/72
3/2/72
Testing at EPA
3/21/72
3/22/72
3/23/72
Testing at GM
4/3/72
4/9/72
LPG
Oxidizing Catalyst
EGR - 2 Stage
Oldsmobile 88
455 CID
HC CO CO 7 NOx
1972
0.32
0.34
0.20
0.27
0.21
0.24
0.17
1975
0.23
0.23
0.19 -
0.15
0.19
0.14
Normal
1972 1975
2.42
0.96
0.70
1.01
0.37
Long Path
1972 1975
1.99
3.10
2.86
1.34 .
1.20
1.61
1.81
1.34
2.28
1.28
0.82
0.97
1.04
1972
902.0
870.9
889.7
1975
866.9
744.4
1972
0.80
0.69
0.79
0.72 .
1.02
0.78
0.73
1975
0.78
0.70
0.75
0.90
0.82
0.73
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