Tighter emmisions standards

It wasn't just 72. "It all started" in 66 in CA and in 68 Federally (U.S.) It got worse every couple / three years. I can still remember in the fall of 66 a local "Chivvie" (dealer) mechanic and some of us were standing around BSing and he was expounding on how "we" would never put up with it, how "we" were going to be rioting in the streets, and on, and on. Of course "we" did none of that. "We" bought the same new cars "we" always did. Some of us threw away the smog pumps.


The manufacturers were some of the last people on earth who wanted to willingly cooperate with either CA or Federal emissions laws. I can assure you they know EXACTLY how engines work. "The cure" (for the OEMs) was EFI. However, that technology simply was not all that advanced back then. There were a few vehicles that DID have EFI, the squareback VW's was one. But even these had their problems

When EFI first came out there were several articles in the popular (no pun intended) hot rod mags about how that and emissions laws was the end of rodding. It's obvious, that was wrong.