Hmmm,

Since my everyday driver is a "smoke belching" Mercedes diesel I do think I know what I am talking about. Correctly maintained these cars do not smoke. My car has never smoked in the entire time I have owned it even when I accelerate heavily even with the 380K it has on it.

Actually the S class diesel was a US market only car made as a stop gap measure to get past the new fuel economy legislation in the 1980's. Considering the 126 chassis and 116 chassis diesels top out at about 110mph they would have never been great cars on the superhighways of europe. My paticular car is unusual as it was a factory delivery that slipped through the federalization process since it was a "US" model. The European lamps on my car and several euro only features were a custom request from the original owner who took delivery in Germany.

Diesel engines very much have a place in modern cars. They have at least double the life expectancy of a gasoline engine and get better fuel economy. On the open highway the torque allows you to pass easily without even downshifting out of your cruising gear. The new VW Jetta and Golf TDI's get 50+ mpg that easily rivals that of hybrid vehicles with 40+ year old technology. The new E class diesel develops more than 200hp.