California Code, Vehicle Code - VEH § 27157.5

The State Air Resources Board, after consultation with, and pursuant to the recommendations of, the commissioner, shall adopt such reasonable standards as it determines are necessary for the public health and safety for the emission of air pollutants from the exhaust of motor vehicles of 1955 through 1965 model years.  These standards shall be based on the normal emissions of such cars when the timing and carburetor are in proper adjustment and the spark plugs are in proper operating condition.