Automobile emissions - the road towards zero
Long the focus of regulators in their efforts to clean up the air, the automobile has become so clean that there are now cases where the air coming out of the tailpipe is cleaner than the surrounding air. However, this progress was not made overnight, nor was it made because of a single technology. Instead, it was a result of continuous improvements by the automobile industry, coupled with necessary improvements to automotive fuels.
This article chronicles the most significant improvements to automobile emissions, beginning with the first controls in the 1960s to the present, and focuses primarily on developments in the United States applicable to gasoline-powered cars and light-duty trucks.