Diesel takes pole position

The car industry isn't famed for its sentimentality, but it still has taboos that have yet to be broken - like the one that says you can't use a diesel engine to power something that purports to be a supercar. That could all change in 2010, though, when this very special prototype goes into production.

This 6 litre V12 diesel-engined evolution of the Audi R8 is the first to combine an oil-burning power-plant with the svelte bodywork of a two-seat supercar. The result isn't just one of the fastest cars the firm has ever built but the quickest, most powerful car of its type.

One press of the engine's big red starter button primes the ignition; the second spins the V12 into life. Responsive and eager to rev, the engine note is strangely muted. There's no soaring wail as engine speeds climb, just a clinical, metallic buzz.

To pull away, simply slot first gear, and lift the throttle. The car's idle speed is set to only 600rpm, yet even at this pace the unit serves up so much torque it will actually power the car right into fourth gear