77-2 AW
Exhaust Emissions from a Ford Pinto Equipped with
the General Dynamics Electrosonic Control System
October 1976
Technology Assessment and Evaluation Branch
Emission Control Technology Division
Office of Mobile Source Air Pollution Control
U.S. Environmental Protection Agency
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Background
The Environmental Protection Agency receives information about many
systems which appear to offer potential for emission reduction or fuel
economy improvement 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,
attempts are made to schedule tests at the EPA Emissions Laboratory at
Ann Arbor, Michigan. The results of all such test projects are set
forth in a series of Technology Assessment and Evaluation Reports, of
which this report is one.
One such system has been developed jointly by General Dynamics and
Autotronic Controls Corporation. This system is called the Electronic
Engine Control System (Electrosonic), and utilizes the principles of
lean-burn combustion to control exhaust emissions.
The Electrosonic system is designed to control engine parameters affecting
exhaust emissions. As such, the system controls ignition timing, air-
fuel ratio and idle speed. The system does have EGR control capability,
although EGR was not on the vehicle supplied to the EPA for evaluation.
The conclusions drawn from the EPA evaluation tests are necessarily of
limited applicability. A complete evaluation of the effectiveness of an
emission control system in achieving performance improvements on the
many 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 the 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.
Test Vehicle Description
The test vehicle was a 1976 Ford Pinto MPG powered by a four cylinder
140 cu in. engine and equipped with a four speed manual transmission.
The Electrosonic system retains the standard compression ratio, mani-
folds and spark plugs. As manufactured, the Pinto was equipped with
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an air pump, EGR and oxidation catalyst, but the Electrosonic system
does not require the use of these control devices. Consequently the
catalyst had been removed from the test vehicle, and the air pump and
EGR had been rendered inoperative. With the exception of these changes,
no other modifications had been made to the engine or vehicle. A list
of pertinent vehicle statistics is given on the Vehicle Information page
at the end of this report.
The Electrosonic system is designed to maintain lean-burn combustion by
monitoring vehicle parameters, operating modes and ambient conditions,
and supplying the correct amount of fuel to match the air-flow through
the engine. Figure 1 is a schematic diagram showing the essential
features of the Electrosonic system. Figure 2 is a flow diagram showing
the input and output signals of the electronic controller.
The information supplied to the controller by the air flow transducer
and the ambient condition sensors allows the controller to determine the
mass flow of air into the engine. Further input information regarding
vehicle operating mode (idle, acceleration, cruise, etc.) is used by the
controller to determine the correct amount of fuel to be fed into the
intake manifold to maintain the desired air-fuel ratio. Fuel is supplied
to the intake system by a fuel metering pump. A conical throttle controls
the engine inlet air.
For the prototype system tested by the EPA, the controller was located
in the trunk and utilized circuit boards for the mounting of electronic
components. For development work, the circuit board approach simplifies
the changing of electronic components. During the EPA test program the
Pinto was tested at two NOx emission calibrations: 2.0 gm/mile and 1.0
gin/mile. The change in calibration was accomplished by changing circuit
boards in the controller. For mass production of the Electrosonic
system, a microprocessor would replace the bulky circuit boards used in
the development version.
Figures 3 and 4 show the actual installation of the Electrosonic system
in the test vehicle.
The air-fuel ratio delivered by the Electrosonic system varies from
approximately 13.5:1 (cold start) to 19.5:1 (cruise). Intermediate air-
fuel ratios are used for acceleration and power enrichment conditions.
Test Program
Exhaust emission and fuel economy tests were conducted in accordance
with the 1975 Federal Test Procedure ('75 FTP) for light-duty vehicles
(Federal Register, June 30, 1975, Vol. 40 No. 126, Part III), and the
EPA Highway Fuel Economy Test (HFET). Evaporative emissions were not
measured.
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Figure 3
Figure 4
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The Pinto was tested at two NOx emission calibrations. The vehicle was
alternately calibrated for a 2.0 gin/mile NOx standard and a 1.0 gm/mile
NOx standard. NOx emissions were expected to be about 25% below the
target standards.
Two inertia weights were used during the test program, 3000 Ib. and 2750
Ib. The 3000 Ib. inertia is correct for the curb weight of the vehicle.
The 2750 Ib. inertia represents the expected inertia for future model
years of the Pinto.
Finally, an optional shift pattern was used during the test program.
This optional shift pattern was used by Ford Motor Company during 1976
certification testing of comparable Pintos. The optional shift pattern
generally calls for shifting into 4th gear when cruise conditions occur
during the emission test. At some points during the test, the trans-
mission is shifted directly from 2nd to 4th gear. For comparative
purposes, one test was conducted using the standard shift speeds specified
in the Federal Register for the '75 FTP. The optional pattern was not
used during the HFET.
The following Table lists the configurations and conditions under which
the Pinto was tested.
Test Program
2.0 gm/mile NOx:
3000 Ib. inertia, optional shift pattern
('75 FTP + HFET) duplicate tests
2750 Ib. inertia, optional shift pattern
('75 FTP + HFET) duplicate tests
1.0 gm/mile NOx:
2750 Ib. inertia, optional shift pattern
('75 FTP + HFET) duplicate tests
2750 Ib. inertia, standard shift pattern
('75 FTP + HFET) single test
After completing the exhaust emission and fuel economy tests, the Pinto
was subjected to a cursory driveability test. For the purpose of the
driveability test, the vehicle was given a short test drive and any
significant driveability faults were noted. The vehicle was warmed up
prior to the driveability test.
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Test Results
The following tables summarize the exhaust emissions and fuel economy of
the Pinto test vehicle.
'75 FTP mass emissions in
grams per mile
(grams per kilometer)
(1)
HC
2.0 gm/mi. NOx 3000 Ib.
inertia opt. shift
2750 Ib. inertia
opt. shift
1.0 gm/mi. NOx 2750 Ib.
inertia opt. shift
2750 Ib. inertia
standard shift
CO
NOx
1.37
(0.86)
1.28
(0.79)
1.19
(0.74)
1.11
(0.69)
3.7
(2.3)
3.2
(2.0)
4.0
(2.4)
3.4
(2.1)
1.73
(1.07)
1.65
(1.03)
1.03
(0.64)
1.09
(0.68)
Fuel Economy
(Fuel Consumption)
26.2 miles/gal.
(9.0 liters/100 km)
26.2 miles/gal.
(9.0 liters/100 km)
24.7 miles/gal.
(9.5 liters/100 km)
23.4 miles/gal.
(10.0 liters/100 km)
(1)
Values in parenthesis denote metric units.
Highway Fuel Economy (Consumption)
2.0 gm/mi. NOx
3000 Ib. inertia
2750 Ib. inertia
1.0 gm/mi. NOx
2750 Ib. inertia
36.7 miles/gal.
(6.5 liters/100 km)
37.2 miles/gal.
(6.3 liters/100 km)
35.9 miles/gal.
(6.6 liters/100 km)
For comparison, the following emissions and fuel economy were measured
from the comparable 1976 certification vehicle.
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'75 FTP mass emissions in
grams per mile ,-v
(grams per kilometer)
Fuel Economy
HC CO NOx (Fuel Consumption)
0.62 2.5 2.63 25 miles/gal.
(0.39) (1.6) (1.63) (9.4 liters/100 km)
Highway Fuel Economy (Consumption)
38 miles/gal.
(6.2 liters/100 km)
Values in parenthesis denote metric units.
The inertia class of the certification vehicle was 2750 Ibs. The fuel
economy of the certification vehicle has been rounded to the nearest
whole mile per gallon figure.
Due to problems with laboratory analysis equipment, it was necessary to
use two dynamometer sites (EPA dynamometers 6 and 7) during the course
of the test program. The data generated on dynos 6 and 7 show a greater
variation in NOx emissions (between the two dynamometers) than would be
encountered as a consequence of normal test variability. Because of
time constraints on the test program, it was necessary to complete the
program without identifying the reasons for the variation in NOx emis-
sions between the two sites. (Subsequent investigations are being made
to identify the reasons for the variation.)
NOx emissions measured from testing on dyno 6 were lower than those
measured on dyno 7. In addition, data measured during tests on dyno 6
were in agreement with data from other test programs conducted by General
Dynamics prior to and following the EPA evaluation.
Details of the individual emission tests, Highway Cycles and steady
states are presented in Tables I-IV following the text of this report.
Individual tests in Table I and II are also identified according to
dynamometer site.
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The driveability test did not reveal any significant driveability
problems. A slight lean surge could be detected under some cruise con-
ditions. Generally, the Pinto did not exhibit the driveability problems
common to lean burn vehicles, i.e., hesitation on accelerations and
significant lean surge, and was rated as Acceptable in EPA'a informal
evaluation.
The fuel economy improvement (during the '75 FTP) due to the optional
shift pattern is roughly 5%. CO emissions are slightly higher when the
optional shift pattern is utilized.
Acceleration times were not measured during the EPA program. However,
General Dynamics has conducted acceleration tests, and found 0-60 mph
acceleration times of 13-14 seconds.
Conclusions
The General Dynamics Pinto demonstrated NOx emissions below 2.0 grams
per mile without incurring a fuel economy penalty (compared to the base-
line 1976 model vehicle). Emissions of HC and CO are well within the
1977 emission standards of 1.5 gms/mi. and 15.0 gms/mi. respectively.
Data supplied to the EPA by General Dynamics indicate that HC emissions
below 0.41 gms/mi. can be obtained with the addition of an oxidation
catalyst.
Because of the nature of this short evaluation program, no conclusions
could be made regarding the durability of this system or the deteriora-
tion factor associated with its use.
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10
Table I
1975 Federal Test Procedure
mass emissions in
grams per mile ,-v
(grams per kilometer)
miles/gal.
Test # HC CO C02 NOx (liters/100 km)
2.0 gm/mi NOx
3000 Ib. inertia, opt. shift
77-4293(2)
77-4331
2750 Ib. inertia,
77-4418
77-4419
1.0 gm/mi. NOx
2750 Ib. inertia,
77-4327
77-4361
77-4397(2)
2750 Ib. inertia,
77-4362
1.33
(0.83)
1.41
(0.88)
opt. shift
1.18
(0.73)
1.37
(0.85)
opt. shift
1.19
(0.74)
1.23
(0.77)
1.14
(0.71)
3.5
(2.2)
3.8
(2.3).
3.0
(1.9)
3.3
(2.0)
3.8
(2.3)
4.1
(2.5)
4.0
(2.5)
323..
(201.)
335.
(208.)
329.
(205.)
331.
(205.)
348.
(216.)
357.
(222.)
342.
(213.)
1.52
(0.94)
1.93
(1.20)
1.75
(1.09)
1.55
(0.96)
1.06
(0 . 66)
1.05
(0.66)
0.97
(0.60)
26.7
(8.8)
25.7
(9.1)
26.3
(9.0)
26.1
(9.0)
24.8
(9.5)
24.2
(9.7)
25.2
(9.4)
standard shift
1.11
(0.69)
3.4
(2.1)
371.
(230.)
1.09
(0.68)
23.4
(10.0)
Values in parenthesis denote metric units.
(2)
Dynamometer 6.
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11
Test #
2.0 gm/mi NOx
3000 Ib. inertia
77-4294(2)
77-4332
2750 Ib. inertia
77-4420
77-4421
1.0 gm/mi. NOx
2750 Ib. inertia
77-4328
77-4356
77-4329
(2)
Table II
EPA Highway Fuel Economy Test
mass emissions in
grams per mile ,. v
(grams per kilometer)
HC
CO
C02
NOx
(1)
(2)
Values shown in parenthesis denote metric units.
Dynamometer 6.
miles/gal.
(liters/100 km)
0.85
(0.53)
0.88
(0.55)
0.78
(0.48)
0.88
(0.55)
0.72
(0.45)
0.68
(0.42)
0.65
(0.41)
1.3
(0.8)
1.3
(0.8)
1.2
(0.8)
1.4
(0.9)
1.6
(1.0)
1.6
(1.0)
1.6
(1.0)
231.
(144.)
243.
(151.)
231.
(143.)
237.
(147.)
243.
(151.)
249.
(155.)
236.
(147.)
1.28
(0.80)
1.62
(1.01)
1.36
(0.85)
1.28
(0.80)
0.72
(0.45)
0.73
(0.45)
0.62
(0.38)
37.6
(6.3)
35.8
(6.6)
37.7
(6.2)
36.7
(6.4)
35.8
(6.6)
35.0
(6.7)
36.9
(6.4)
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Table III
1975 Federal Test Procedure
Individual Bag Emissions in
grams per mile
Test #
Bag 1: Cold Transient
HC NOx CO 2 CO MPG
Bag 2: Stabilized
HC NOx C02 CO MPG
Bag 3: Hot Transient
HC NOx C02 CO MPG
2.0 gm/mi. NOx
3000 Ib. inertia, opt. shift
77-4293
77-4331
2750 Ib.
77-4418
77-4419
1.0 gm/mi
2750 Ib.
77-4327
77-4361
77-4397
1.60 2.13 322.
1.70 2.72 339.
inertia, opt. shift
1.36 2.45 327.
1.65 2.14 327.
. NOx
inertia, opt. shift
1.60 1.58 339.
1.65 1.61 355.
1.58 1.54 341.
5.9
6.2
4.9
5.1
6.6
6.1
5.8
26.4
25.1
26.2
26.1
25.0
24.0
25.0
1.30
1.31
1.17
1.31
1.12
1.13
1.02
1.05
1.39
1.28
1.13
0.74
0.74
0.65
343.
350.
348.
349.
369.
379.
360.
3.0
2.6
2.5
2.8
2.8
3.5
3.4
25.2
24.8
25.0
24.8
23.5
22.9
24.1
1.19
1.38
1.07
1.25
1.03
1.10
1.05
1.94
2.37
2.14
1.90
1.29
1.24
1.13
287.
304.
296.
298.
313.
319.
310.
2.8
4.2
2.6
2.8
3.5
3.6
3.8
30.1
28.1
29.3
28.9
27.6
27.0
27.8
2750 Ib. inertia, standard shift
77-4362 l;34 1.58 360. 4.9 23.9 1.08 0.80 396. 3.0 22.0 0.99 1.28 331. 3.0 26.2
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13
Table IV
2.0 gm/mi. NOx
3000 Ib. inertia
idle (neutral)
15 mph (24kph)
2nd gear
30 mph (48 kph)
4th gear
45 mph (72 kph)
4th gear
60 mph (97 kph)
4th gear
2750 Ib. inertia
15 mph (24 kph)
2nd gear
30 mph (48 kph)
4th gear
45 mph (72 kph)
4th gear
60 mph (97 kph)
4th gear
1.0 gm/mi NOx
2750 Ib. inertia
idle (neutral)
Steady State mass emissions in
grams per mile ,. -.
(grams per kilometer)
HC
CO
CO,
NOx
miles/gal
(Liters/100 km)
7.31
gms /hr
2.80
(1.74)
1.04
(0.64)
0.85
(0.53)
0.86
(0.53)
2.42
(1.50)
1.04
(0.65)
0.79
(0.49)
0.79
(0.49)
7.39
gm/hr
24.0
gms /hr
2.8
(1.7)
1.0
(0.6)
1.1
(0.7)
1.2
(0.8)
2.7
(1.7)
1.0
(0.6)
1.1
(0.70)
1.2
(0.8)
22.4
gm/hr
3118.
gms /hr .
294.
(182.)
188.
(117.)
209.
(130.)
244.
(151.)
292.
(181.)
185.
(115.)
201.
(125.)
233.
(145.)
3069.
gms /hr .
1.68
gms/hr
0.15
(0.10)
0.23
(0.15)
0.70
(0.43)
2.00
(1.25)
0.15
(0.10)
0.18
(0.11)
0.57
(0.36)
1.66
(1.03)
1.51
gms/hr
2.8
(10.
28.9
(8.1)
45.9
(5.1)
41.6
(5.7)
35.7
(6.6)
29.2
(8.0)
46.7
(5.0)
43.2
(5.4)
37.3
(6.3)
2.8
(10.6
(10.6 liters/hr.)
(1) Values in parenthesis denote metric units.
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Table IV (con't)
Steady State mass emissions in
grams per mile ,..-.
(grams per kilometer)
miles/gal
HC CO C02 NOx (Liters/100 km)
15 mph (24 kph) 2.47 3.0 306. 0.14 27.8
2nd gear (1.53) . (1.9) (190.) (0.09) (8.5)
30 mph (48 kph) 0.98 1.2 199. 0.14 43.6
4th gear (0.61) (0.8) (123.) (0.09) (5.4)
45 mph (72 kph) 0.73 1.3 218. 0.33 39.9
4th gear (0.46) (0.8) (135.) (0.21) (5.9)
60 mph (97 kph) 0.71 1.6 251. 0.80 34.7
4th gear (0.44) (1.0) (156.) (0.50) (6.8)
(1) Values in parenthesis denote metric units.
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TEST VEHICLE DESCRIPTION
Chassis model year/make - 1976 Ford Pinto MPG
Emission control system - Lean-Burn combustion
Engine
type 4 stroke, Otto cycle, 1-4, ohc
bore x stroke 3.78 x 3.13 in./96.0 x 79.5 mm
displacement 140 cu in./2295 cc
compression ratio 9.0:1
maximum power @ rpm not available
fuel metering metering pump
fuel requirement unleaded
Drive Train
transmission type 4 speed manual
Chassis
type front engine, rear wheel drive
tire size A78 x 13
curb weight 2575 lbs./1168 kg
inertia weight see text
passenger capacity 4
Emission Control System
basic type lean-burn combustion
durability accumulated on system. . 7500 mi./12100 km
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