Would you drive a diesel powered American car if one were avalible at a decent price?

No - diesel engines emit particulate which is very harmful. Further, I think we can do better than the 22% (maximum) efficiency that internal combustion can provide. We waste 3/4s of the potential energy of fuel with internal combustion engines. Certainly, while improvements have been made, there ought to be better technology than that which is 130 years old.