Click here for more pictures of the Audi R8 V12 TDi

Audi has unveiled the world’s first road-going diesel-powered supercar at the 2008 Detroit Motor Show – the concept Audi R8 V12 TDi.

Featuring a twin-turbocharged 6-litre V12 diesel engine, the concept R8 produces 500bhp and a whopping 737 lb/ft of pulling power – eclipsing the V8 petrol-powered Audi R8 which produces 414bhp and 317 lb/ft.

This means a 0-62mph time of 4.2 seconds and a top speed at “well over” 186mph, marking the concept Audi R8 V12 TDi as the world’s fastest diesel sportscar.

The monster V12 engine – the same unit used for the Audi Q7 V12 TDi – is mated to a six-speed gearbox and the diesel R8 will feature Audi’s Quattro four-wheel-drive system.

But for those fearing the gorgeous Audi will have lost its appeal thanks to a diesel clatter, engineers at the Ingolstadt firm have said the R8 V12 TDi sounds “full-bodied and is equipped with energetic overtones.”

Official consumption figures have not been released, but Audi claims the diesel R8 will meet forthcoming Euro 6 regulations due in 2014.

The concept R8 is distinguished by a glass roof and engine cover, larger wheel arches, bigger air intakes, more pronounced side-skirts and an aluminium spoiler.

The diesel-powered Audi R8 caps off a successful period for the German marque – the Audi R10 TDi Le Mans racing car won its first endurance race in 2006 when pitted against a field of petrol-powered racers, and more recently swept the board in 2007.

Click here for more pictures of the Audi R8 V12 TDi