The Federal Government has placed stringent standards on the manufacturers of automobiles to control vehicle emissions. Few states standards have been set for used vehicles to insure the vehicle continues to meet this standard. Studies have shown that vehicles that are properly tuned are emitting less harmful pollutants from the exhaust. Additional studies are needed to determine if cars are being adequately turned to meet exhaust emissions. The study showed 93 per cent of the new 1971 model cars were not meeting the standard established by the Environmental Protection Agency. Eighty-seven per cent of the 1970 model cars and 83 per cent of the used 1971 model cars tested would not meet the same standards. There was a very low correlation between emission level and the mileage driven since the vehicle was tuned indicating a need for more emphasis on tune-ups and maintenance of automobiles to meet emission standards.