Air Care Colorado

Emissions Limits for 1981 and Older Light-Duty Vehicles

1981 and older vehicles are tested with the two-speed idle test. Pollutants are sampled and measured in parts per million. Oxides of nitrogen are not measured in the idle test.

1981 & Older Light-Duty Passenger Vehicle Limits
(Includes Light-Duty Trucks)

Model YearCOHC
1970 & Earlier3.51000
19713.01000
19723.01000
19733.01000
19743.01000
19752.0600
19762.0600
19771.5400
19781.5400
19791.5400
19801.5400
1981 & Newer1.2220

CO: carbon monoxide   HC: hydrocarbons
Source: Colorado Department of Public Health and Environment