Diesel cars in the 70's, the US models in particular, were poorly thought out. Even the decent ones (from Germany and Japan) were smelly, noisy beasts that people just didn't like having to deal with. Probably the worst thing for the diesel rep came with the GM diesel 350. They took a gasoline engine (the good ol' 350) and converted it to diesel... the results were unimpressive.

So, anyone who lived through the 70's and 80's is likely to still harbor some bad feelings toward diesel cars.