EPA-AA-TEB-8 2-3
Emissions and Fuel Economy of the
Dresser Economizer, a Retrofit Device
By
Stanley L. Syria
December 1981
Test and Evaluation Branch
Emission Control Technology Division
Office of Mobile Source Air Pollution Control
U.S. Environmental Protection Agency
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Abstract
This report describes the results of testing the Dresser Economizer as
part of an evaluation under Section 511 of the Motor Vehicle Information
and Cost Savings Act. This device is a gasket which is installed between
the intake manifold and the cylinder head. The size of each passage is
approximately half that of the original unit. Such a constriction
increases the velocity and turbulence of the incoming charge. This is
claimed to cause a more homogenous mixture and result in improved fuel
economy and driveability, especially when the engine is cold. The
primary purpose of this project was to evaluate the effect of the Dresser
Economizer on fuel economy and levels of exhaust emissions. Secondary
purposes were to measure any loss in vehicle power and possible changes
in driveability.
Testing of three recent model year passenger cars was conducted at EPA's
Motor Vehicle Emission Laboratory during September and October of 1981.
The basic test sequence included the Federal Test Procedure (FTP) and the
Highway Fuel Economy Test (HFET). These tests were performed both before
and after installation of the Dresser Economizer and again after
restoration of the vehicle. Except for a 2% decrease in the average
hydrocarbon emissions for the HFET, all regulated emissions were slightly
increased. Fuel economy was found to decrease approximately one percent
on the FTP and two percent on the HFET. None of these changes were found
to be statistically significant. Vehicle performance was not noticeably
affected.
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Background
Section 511' of the Motor Vehicle Information and Cost Savings Act
empowers the Environmental Protection Agency (EPA) to evaluate devices
which may improve fuel economy of conventional motor vehicles. The EPA
has developed and instituted a procedure whereby an individual or
organization may apply for an evaluation of the device or fuel additive.
This procedure requires the applicant to submit a technical description
of the system in conjunction with results from actual testing. Once a
complete application is received, the EPA will conduct an engineering
evaluation and publish the results in the Federal Register. In those
cases where the device shows promise, the EPA will conduct its own tests
as a part of the evaluation. Such testing is performed at EPA's Motor
Vehicle Emission Laboratory in Ann Arbor.
In June, 1981, EPA received an application from Dresser Industries for an
evaluation of the Dresser Economizer. This device was claimed to improve
the fuel economy and driveability of light duty vehicles with carbureted
gasoline engines. Based on an evaluation of the test results submitted
to support the claims for the device, EPA chose to conduct confirmatory
testing. The primary purpose of the testing was to determine the effect
of the device on fuel economy and exhaust emissions. Secondary purposes
included an evaluation of the vehicle performance and other driveability
factors.
Description of the Device
The Dresser Economizer is a gasket which is installed between the intake
manifold and the cylinder head. It replaces the original unit. The area
of each passage is approximately half of that in the OEM version with a
slight bell mouth shape formed at each port. Such a constriction
increases the velocity and turbulence of the incoming charge. This is
said to cause a more homogenous mixture and result in improved fuel
economy and driveability, especially when the engine is cold.
Program Design
Three typical recent production vehicles were used: a Plymouth Volare
with a 6-cylinder engine; an Oldsmobi'le Cutlass with a 6-cylinder engine;
and a Chevrolet Nova with an 8-cylinder engine. All vehicles were
equipped with automatic transmissions. A more detailed description of
each vehicle is provided in Appendix A.
Exhaust emission tests were conducted according to the 1977 Federal Test
Procedure (FTP) described in the Federal Register of June 28, 1977, and
the EPA Highway Fuel Economy Test (HFET) described in the Federal
Register of September 10, 1976. The vehicles were not tested for
evaporative emissions. Indolene fuel was used for all testing.
In addition to the exhaust emission tests, engine power was also
evaluated at each step by performing wide-open-throttle (WOT)
accelerations from 5 mph to 60 mph while on the chassis dynamometer. The
elapsed time was measured with a stop watch. Driveability was also
observed at all times.
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The following test sequence was employed. This test sequence had been
previously approved by the applicant.
1. Adjust engine parameters to manufacturer's specifications.
2. Conduct triplicate acceleration tests.
3. Conduct duplicate baseline FTP and HFET sequences.
4. Install device.
5. If detonation is noticed, retard the basic timing by two degrees.
6. Conduct triplicate acceleration tests.
7. Conduct duplicate FTP and HFET sequences.
8. Remove device.
9. Conduct triplicate acceleration tests.
10. Conduct duplicate FTP and HFET sequences.
11. If timing was adjusted as part of the installation, return the
vehicle to manufacturer's specifications.
12. Conduct triplicate acceleration tests.
13. Conduct duplicate FTP and HFET sequences.
Conduct of the Program
Installation of the Dresser Economizer on the test vehicles was performed
in accordance with the instructions provided by the applicant. The
procedures for each vehicle were observed and approved by James Pince of
Dresser Industries. Each installation required approximately four
man-hours.
Following each installation, the engine was audibly checked for
detonation under a number of driving conditions. Detonation was not
observed for any vehicle. Thus, timing was not adjusted and steps 5, 11,
12 and 13 of the test plan were not performed.* All vehicles were
checked with a Sun engine analyzer to assure no changes had occurred.
The vehicles were tested during September and October of 1981. All tests
were performed by EPA at the Motor Vehicle Emission Laboratory in
Ann Arbor. The test sequence was conducted as written except the
measurements for acceleration time required in Step 9 were not
conducted. However, we determined that this oversight did not adversely
affect the results of the program since no spark advance was changed and
the subsequent emission tests were essentially identical to the baseline
tests.
Test Results
Tables 1 and 2 summarize the results of this testing. Emission levels
are listed in grams per mile while fuel economy is shown in miles per
gallon. The results of the individual tests on each vehicle are
presented in Appendices B, C, and D. Although these appendices include
the test results after the vehicles were restored, these values were not
used in developing Table 1. These tests were performed to assure that
the engine had not changed during the testing or as a result of the
mechanical work required to install and remove the device.
*Because removal of the intake manifold on the Nova also required the
removal of the distributor, the initial timing was reset after
reinstallation of all components.
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Table 1
Summary of Emission Test Results
B TP HFET
Vehicle
Plymouth
Volare
Chevrolet
Nova
Old smo bile
Cutlass
Overall
Fleet
Configuration
Baseline
Device
Ave. Change
Baseline
Device
Ave. Change
Baseline
Device
Ave . Change
Baseline
Devi ce
Ave. Change
HC
.74
.78
5%
.94
1.08
15%
1.04
1.04
0% .
.91
.97
7%
CO
8.7
10.6
22%
14.4
15.4
7%
10.8
10.3
-5%
11.3
12.1
7%
NOx
.89
.85
-4%
1.60
1.79
12%
1.20
1.38
15%
1.23
1.34
9%
F.E.
18.99
18.47
-2.7%
13.10
13.02
-0.6%
18.98
19.05
0.4%
16.51
16.35
-1.0%
HC
.84
.76
-10%
.22
.25
14T
.15
.16
7%
.40
.39
-2%
CO
20.6
20.3
-1%
0.2
0.3
501
1.6
2.0
25%
7.5
7.5
0%
NOx
.58
.48
-17%
2.55
2.72
JT~
1.46
1.84
"26%"
1.53
1.68
10%
F.E.
25.78
24.88
-3.5%
17.78
17.29
-2.8%
25.74
25.70
-0.2%
22.41
21.91
-2.2%
Note: Emission results are in grams per mile. Fuel economy values are in
miles per gallon.
Table 2
Summary of WOT Acceleration Test Results
Vehicle
P lymouth
Volare
Average
Chevrolet
Nova
Average
Oldsmobile
Cutlass
Average
Run
1
2
3
1
2
3
1
2
3
5-60 mph
Baseline
15.2
15.0
15.0
15.1
11.4
11.2
11.4
11.3
15.6
15.8
15.8
15.7
time (sec)
Device
16.6
16.2
16.4
16.4
11.2
11.6
11.4
TO"
16.8
16.8
16.8
16.8
Average
Change
9%
1%
7%
Overall 14.0 14.9 6%
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Using the Student's "T" test, a statistical analysis was made of the
exhaust emission and fuel economy data. At a 95% confidence level, this
analysis indicated that there were no significant changes in the average
fleet emission or fuel economy levels.
Although the evaluation was subjective, driveability of the vehicles
under both cold and warm conditions was not noticeably affected. The
only exception was acceleration rate at WOT. Even this loss was not to a
degree that would be noticed by most drivers.
Conclusions
In general, the Dresser Economizer was found to have no significant
effect on emissions, fuel economy or performance. More specific findings
are as follows:
1. The installation instructions were found to be adequate.
2. Use of the Dresser Economizer resulted in an average increase in
hydrocarbon emissions of 7% for the FTP and a decrease in
average emissions of 2% for the HFET.
3. Carbon monoxide emissions were increased an average of 7% and 1%
for the FTP and HFET, respectively.
4. Oxides of nitrogen were increased an average of 8% and 10% for
the FTP and HFET, respectively.
5. Use of the Dresser Economizer resulted in a 1% decrease in fuel
economy on the FTP and a 2% decrease on the HFET.
6. Average acceleration time from 5 mph to 60 mph was increased
approximately 6%.
7. Cold/hot starting and cold/hot performance was not noticeably
affected.
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Make/Model
Model Year
Type
Vehicle I.D.
Initial Odometer
Engine Type
Configuration
Displacement
Fuel Metering
Fuel Requirement
Transmission
Tires
Inertia Weight
Actual HP (§50 mph
Appendix A
Test Vehicle Descriptions
Plymouth Volare Oldsmobile Cutlass
1979
2 door
HL29C9B217336
31809
Spark Ignition
In-line 6
225 CID
IV Carburetor
Unleaded
Automatic
D78X14
3500
11.3
1979
2 door
3R47A9M523280
35670
Spark Ignition
V6
231 CID
2V Carburetor
Unleaded
Automatic
P195/75R14
3500
12.2
Emission Control Systems EGR
Catalyst
Air Injection
EGR
Catalyst
Air Injection
Chevrolet Nova
1975
2 door
1X27L5L115735
7243
Spark Ignition
V8
350 CID
4V Carburetor
Unleaded
Automatic
ER78X14
4000
12.0
EGR
Catalyst
Air Injection
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Test
Date
Test
//
9-29-81 810947
9-29-81 810948
9-30-81 810949
9-30-81 810950
10-6-81 8109 51
10-6-81 810952
10-7-81 810953
10-7-81 810954
10-14-81 810955
10-14-81 810956
10-15-81 810957
10-15-81 810958
Appendix B
Test Results - Plymouth Volare
FTP
Config-
uration
HFET
HC
Baseline 0.70
Baseline
Baseline 0.78
Baseline
CO NOx F.E.
9.0 0.88 18.89
8.4 0.90 19.08
Device
Device
Device
Device
0.74 11.6 0.83 18.45
0.82 9.7 0.88 18.48
Restored 0.63
Restored
Restored 0.69
Restored
9.0 0.96 18.47
9.3 0.93 18.52
HC CO NOx F.E.
0.77 19.1 0.56 25.67
0.92 22.1 0.61 25.88
0.87 22.1 0.53" 24.95
0.66 18.6 0.44 24.82
0.54 15.2 0.42 25.66
0.51 14.7 0.39 25.88
Note: Emission results are in grams per mile. Fuel economy values are in
miles per gallon.
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Appendix C
Test Results - Chevrolet Nova
Test
Date
10-1-81
10-1-81
10-2-81
10-2-81
10-7-81
10-7-81
10-8-81
10-8-81
10-28-81
10-28-81
10-29-81
10-29-81
Test
#
810969
810970
810985
810986
810971
810972
810973
810974
810981
810982
810983
810984
Config-
uration
Baseline
Baseline
Baseline
Baseline
Device
Devi ce
Device
Device
Restored
Restored
Restored
Restored
HC
0.94
0.93
1.10
1.05
0.85
0.77
CO
14.8
13.9
15.7
15.1
10.6
9.4
FTP
NOx
1.58
1.63
1.90
1.68
1.75
1.80
HFET
F.
13
13
13
12
13
13
E.
.02
.19
.08
.95
.24
.30
HC
0.22
0.22
0.26
0.24
0.21
0.20;
CO
0.2
0.2
0.4
0.2
0.2
0.1
NOx
2.56
2.54
2.72
2.71
2.52
2.47
F.E.
17.67
17.89
17.25
17.33
17.89
17.82
Note: Emission results are in grams per mile. Fuel economy values are in
miles per gallon.
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10
Appendix D
Test Results - Oldsmobile Cutlass
Test Test Config- FTP
Date #
uration HC CO NOx F.E.
HFET
HC CO NOx F.E,
9-29-81 810987
9-29-81 810988
9-30-81 810989
9-30-81 810990
10-6-81 810991
10-6-81 810992
10-7-81 810993
10-7-81 810994
10-14-81 810995
10-14-81 810996
10-22-81 811001
10-22-81 811002
Baseline 1.03 11.0 1.20 18.85
Baseline 0.12
Baseline 1.06 10.5 1.20 19.12
Baseline 0.18
Device
Devi ce
Device
Device
1.10 10.6 1.32 19.15
0.99 10.0 1.43 18.95
Restored 0.87
Restored
Restored 0.85
Restored
9.2 1.29 18.86
8.9 1.25 19.21
0.18
0.15
0.08
0.12
1.2 1.50 25.68
2.1 1.43 25.79
2.1 1.80 25.86
1.8 1.87 25.53
0.7 1.49 25.68
1.2 1.48 25.76
Note: Emission results are in grams per mile. Fuel economy values are in
miles per gallon.
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