Before looking at the new R18 TDi here is an evolutionary look at Audi at Le Mans since 1999.
In 1999 Audi had two different approaches to the 24 hours, the R8C coupe…
and the open prototype Audi R8R…
In 2000 Audi won Le Mans with the Audi R8. Audi dominated at Le Mans with this car, winning in 2000, 2001, 2002, 2004 and 2005.
In 2006 Audi launched the R10 TDi, a V12 turbo diesel rather than the V8 petrol turbo that they had used in the R8 and Speed 8. It won at Le Mans in 2006, 2007 and 2008.
In 2007 Peugeot launched their 908 turbo diesel which while proving faster than the R10 TDi, was much more fragile. In 2009 Audi launched their successor to the R10 Tdi, the R15 TDi. The R15 TDi used a V10 turbo diesel engine. This car proved to be little faster than the R10 TDi and was beaten by the Peugeots in 2009, although it did win Le Mans in 2010 mainly due to the Peugeots unreliability.
In December 2010 Audi released the R18 TDi, which will use a V6 turbo diesel engine.