When was positive crankcase ventilation first adopted on U.S. cars? Why was it adopted? Many sources, including some academic textbooks, will tell you it was required by California regulations starting in 1961, but that’s not true at all. Here is the full story of how the American auto industry found a new use for an old technology and briefly promoted positive crankcase ventilation as a cheaper alternative to auto exhaust controls, only to immediately reverse course and spend the next few years fighting tooth and nail against regulations that would require crankcase emissions controls for all new cars and trucks.

A closed crankcase ventilation system. (Illustration from a November 1977 EPA publication; believed in the public domain in the United States)

Continue Reading Science, Skullduggery, and Bad Faith: How the U.S. Auto Industry Adopted Positive Crankcase Ventilation

Few things have had a greater influence on the design and engineering of modern automobiles than emissions control regulations. First initiated in California in the fifties and sixties, legislative and regulatory efforts to limit motor vehicle emissions soon became a model for U.S. federal standards, which in turn helped to shape environmental law in other countries. In this installment of Ate Up With Motor, we present a timeline of the major early events and developments in governmental control of auto emissions, from the 1940s through the end of the 1960s.

San Gabriel, Los Angeles County, California, in May 1972. (Photo: “LOW-HANGING SMOG” by Gene Daniels / Environmental Protection Agency via the National Archives and Records Administration; in the public domain in the United States)

Continue Reading Before the Muskie Act: Early Emissions Law and Regulation, 1940–1969