Environmental regulations have had something to do with the reluctance of US manufacturers to embrace diesel tech like the rest of the world. The technology is still new to the US and rapidly improving.
The EPA came first and promulgated responsibility for compliance to the States. CARB came after EPA in the early 1970s. I used to be in the consulting business.
Diesel engines have some inherent advantages like hp/torque, efficiency, longevity, and higher mpg. A diesel engine at 175k miles is not even half way done, when most gas engines are near the end of their lives.
Diesels can run on all sorts of unrefined fuels and those made from bio waste. We will be seeing more diesels in the future, not less. Ford will soon have a diesel 1/2 ton pu like the Dodge version that is already on the market.
