We've had our fingers crossed that Audi would eventually bring the R8 V12 TDI to market, but according to an AutoExpress source, that's just not going to happen. Why, Audi? Why?

AutoExpress sources claim the development costs associated with re-engineering the Audi R8 to house the massive twin-turbo diesel V12 would be too great and that Audi would be unable to reap a return in its investment through sales.

The concept Audi R8 V12 TDI made its world debut at the Detroit Auto Show in 2008, sporting aggressively revised bodywork and a 500-horsepower and 737 lb-ft. of torque, 5.5-liter TDI V12 from the Audi R10 Le Mans racer. Needless to say, it would have been nice to see some of Audi's diesel knowledge from its racing endeavors on the street. [wcf via autoexpress]