Aircare question....

My best recollection is they started in 1975 in the U.S. Not all cars got them right away though. I remember some foreign cars didn't need them that soon. Cars that required unleaded fuel (because of the catalytic converters) should have a smaller filler tube opening where you put in the gas. The unleaded pumps had a smaller nozzle than the leaded pumps. That way you could put an unleaded nozzle into an unleaded filler neck but the leaded nozzle wouldn't go into the unleadded neck.