The Motor Vehicle Air Pollution Control Act of 1965 was the first real vehicle pollution control act and it limited certain tailpipe emissions. However, it was

The Motor Vehicle Air Pollution Control Act of 1965 was the first real vehicle pollution control act and it limited certain tailpipe emissions. However, it was one of the stupidist regulations ever, since it limited the proportion of unburned hydrocarbons, etc., in exhaust gas. The auto manufacturers did the rational thing and met the requirements by increasing the displacement of engines and pumping more air in a leaner mixture. The result was poor performing gas guzzlers and fleet mileage dropped from the mid 60s to the mid 70s. Thus, a decade of misguided federal clean air regulations made the oil crises much worse than they would have been. The regulations should have limited grams of pollutant per ton-kilometer in order to require both less pollutants and better efficiency.