OK perhaps supercars is over the top, but I would like to know, as a friend asked me, why they don't make the sportier cars, AMG, RS etc with rechipped diesel engines. OK, back a few years diesels were slow on acceleration, noisey,rattly things, but with the advancements, I am sure performance of a diesel is getting closer to petrol engines. I have noticed that you can now buy coupes in diesels which untill recently you could not, and VW make a Gold GTi with a 155bhp diesel engine. Are there any real or other reasons why no diesel "supercars"