|  The new Audi R10 TDI has written a piece of motorsport history making its début at Sebring (USA) : For the first time ever, a diesel powered car has claimed pole position in a sportscar race. In Thursday’s qualifying session, Scotland’s Allan McNish broke the track record by over two seconds, impressively underlining the performance of the modern Audi TDI technology.
The new Audi R10 TDI is powered by a completely new 5.5-litre, twelve-cylinder bi-turbo TDI engine which is extremely economical and quiet. The Le Mans Prototype, with over 650 hp and more than 1100 Newton metres of torque, significantly exceeds the power produced by the majority of previous Audi racing cars – including that of its victorious R8 predecessor. The R10 prototype’s V12 power unit, which is equipped with two diesel particle filters, is hardly recognisable as a diesel thanks to the engine’s smooth running. The TDI engine’s specialities presented the Audi Sport engineers with many new challenges.
The injection pressure easily exceeds the 1,600 bar achieved in production cars. The usable power band lies between 3,000 and 5,000 revs per minute - an unusually low rev range for a racing engine. The driver can change gear in the R10 far less often than in the R8 because of the TDI engine’s favourable torque curve.
The Audi R10 has a significantly longer wheel base than the R8. The overly wide front tyres are, up until now, unique for a Le Mans Prototype. New technologies were also implemented during the development of the carbon-fibre monocoque. Chassis, engine and gearbox form an extremely rigid, fully stressed unit. | 