74-9 RBM
An Evaluation of a 1976 Prototype Questor Datsun
August 1973
Emission Control Technology Division
Office of Air and Water Programs
Environmental Protection Agency
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Background
EPA has previously tested the Questor emission control system
on two 5000 Ib. inertia weight vehicles with results below
1976 emission levels at low mileage and agreed to test the
system on a lighter vehicle. A Datsun 1800 with an inertia
weight of 2500 Ibs. was supplied for evaluation.
Vehicle Tested
The Questor "Reverter" system was installed on a 1973 Datsun
1800 with a 109 CID engine and automatic transmission. The
heart of the emission control system is a non-noble metal
reduction catalyst sandwiched between partial thermal reactors.
Carburetor calibration and exhaust port air injection rates are
set such that a reducing atmosphere is still present after the
exhaust gas passes through the first partial thermal reactor
stage. After the exhaust gas passes through the NOx catalyst,
additional air is added to complete combustion of the remaining
HC and CO. EGR is not used. Details of this system can be
seen in report 73-9, "A Second Evaluation of the Questor Emission
Control System", published November 1972 by ECTD. No mileage
had been accumulated on this system when it was received in the
EPA laboratory.
Test Program
The vehicle was tested according to the 1975 Federal Test
Procedure as outlined in the November 15, 1972, Federal Register
for light duty vehicles. Fuel economy was calculated by weighing
the amount of fuel used during each test.
Test Results
The test results are presented below, along with fuel economy:
Test No. HC_ C£ NOx MPG
16-552 .11 3.60 .17 16.9
16-558 .13 3.61 .16 16.9
AVERAGE .12 3.60 .16 16.9
'76 levels .41 3.40 .40
A 1973 Datsun certification vehicle with an 1800 engine and
automatic transmission achieved 20J.9 mpg while two similar
certification vehicles with manual transmissions achieved an
average of 18.2 mpg. Compared to the certification vehicle
with an automatic transmission, the Questor Datsun suffered
a 24% fuel economy penalty.
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Conclusions
The Questor Datsun did not meet the 1976 levels, being high
in CO emissions. The HC and NOx emissions were significantly
below the standards. It was indicated that if Questor had had
more time to properly calibrate the vehicle all of the emission
levels could have been met at low mileage. A significant fuel
economy penalty was associated with this emission control system.
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