Last spring at the Geneva Motor Show, Audi introduced the first diesel powered version of its TT sports car, but so far has they have given no indication that they will ever bring it to the US market. Over in Europe the TT TDI is rated at a combined 44.3 mpg (US). The TT is using the same 168 hp 2.0L TDI four cylinder VW is using in the Jetta TDI cup race cars
(the US spec Jetta TDI road cars use a 140 hp variant of the same engine). The folks at Popular Mechanics got to go over to the UK and take a TT TDI for a spin and came home impressed by the performance and fuel efficiency. In the course of some aggressive back road and inner city driving, they managed 39.1 mpg (US). The diesel engine easily revs to its 5,000 rpm redline and as with other diesels it exhibits strong acceleration at speed. The TDI rides a little harder than the gas powered version to compensate for the heavier engine. Now if Audi would just bring this one to the US we'd be all set.
[Source: Popular Mechanics