State of California

Los Angeles Convention Center
1201 South Figueroa Street
Room 202
Los Angeles, CA

November 23, 1976
10:00 a.m.


76-22-1 Approval of Minutes of September 20, Board Meeting.

76-22-2 Public Hearing on Proposed Changes to Regulations for
Exhaust and Evaporative Emission Standards and Test
Procedures for 1979 and Subsequent Passenger Cars,
Light Duty Trucks, and Medium Duty Vehicles.

76-22-3 Other Business

ITEM NO.: 76-22-2(a)

Public Hearing on Proposed Changes to Regulations Regarding
Exhaust Emission Standards and Test Procedures for 1979 and
Subsequent Passenger Cars, Light-Duty Trucks, and Medium-Duty


Adopt Resolution 76-44.


Staff analysis indicates that substantial air quality improvement
is necessary to attain ambient air quality standards throughout
much of the state and that further exhaust emission control of
passenger cars, light-duty trucks and medium-duty vehicles is a
technologically feasible and cost/effective means of obtaining a
portion of the necessary improvement. Adequate lead time exists
for the passenger car NOx emission standard to be reduced from
the 1977 level of 1.5 grams per mile (gpm) to 1.0 gpm by model
year 1980. Based on comments received during the ARB/Industry
workshop held on October 7 and 8, 1976 it appears that compliance
with a 1.0 gpm NOx standard can be accomplished by the
application of 3-way catalyst control systems on some vehicles
and refined oxidation subsequent model years the staff concludes
that industry-wide achievement of a NOx standard of 0.4 gpm is
possible using 3-way catalysts, but without the use of fuel
injection systems or as much noble metal as was used by Volvo in
certifying its four cylinder vehicles at 0.4 NOx for the 1977
model year.

In addition to tightening the light duty truck (LDT) emission
standards it is recommended that the LDT class be broken into two
subclasses, one for vehicles of test weight of below 4000 lbs. and
the other for vehicles with test weights of 4000 lbs. or greater.
Since trucks have a greater variety of functions and load
carrying capabilities than do passenger cars it is felt that some
allowance should be provided for those trucks which must have a
higher test weight and correspondingly higher axle ratios (and
therefore more difficulty in meeting gram/mile emission
standards) by virtue of the functions they are designed to

Tightening of the light-duty truck hydrocarbon standard is
recommended for the 1979 model year, the earliest model year for
which there will be adequate lead time for system changes. For
the 1979 model year, it is recommended that the current standards
of 0.9 HC/17 CO/2.0 NOx be reduced to 0.41 HC/9.0 CO/1.5 NOx for
the below 4000 lb. trucks. For trucks of 4000 lbs. test weight
and above standards of .50 HC/9.0 CO/2.0 NOx are recommended.

After two years at the more stringent standards, it is
recommended that for 1981 the below 4000 lb. NOx standard for
LDT's be the same as the 1.0 gram level proposed for passenger
cards in 1980. For LDT's of 4000 lbs. and above, a NOx standard
of 1.5 is recommended. These standards are expected to require a
level of control that is similar to that required of 1980-81
model passenger cars.

It is also recommended that the 1981 standards for medium-duty
vehicles (6001 to 8500 lbs. GVW) be reduced from 0.9 HC/17 CO/2.3
NOx to .50 HC/9.0 CO/1.5 NOx for test weights up to 5999 lbs. and
.60 HC/9.0 CO/2.0 NOx for test weights above 5999 lbs.

Further NOx reductions for light and medium-duty classes are
proposed for 1983 and subsequent model years. Standards for
LDT's of below 4000 lbs. are proposed to be reduced to 0.4 NOx
and standards for LDT's of above 4000 lbs. are proposed to be
established at 1.0 gram/mile.