If I am not mistaken, after the 1986/1987 fiasco with the trap oxidizer, Mercedes in 1995 installed the first true catalytic converter in the E300D. It was the first use of such a device in an application similar to gas powered automobiles. I believe all diesel Mercs sold in Europe since 1995 have cats installed. It is indeed a shame that excellent vehicles such as the E290CDI as well as other diesels available in Europe cannot come to the U.S. due to certain theories about emission controls.The Audi A8 TDi twin turbo has some 250Hp and god knows how much torque, at 35MPG on the autobahn it is probably one of the best all around oil burners in the world. What I think Washington fails to recognize is that diesel powered cars are 30-40% more eficient that gas powered automobiles, therefore there is less consumption, less polution generated by prospection and refining processes, etc... Just my .02.