The Audi R8 is a Le Mans Prototype sports-prototype race car introduced in 2000 for sports car racing as a redevelopment of their Audi R8R (open-top LMP) and Audi R8C (closed-top LMGTP) used in 1999. In its class, it is one of the most successful racing sports cars having won the 24 Hours of Le Mans race in 2000, 2001, 2002, 2004, and 2005, five of the six years it competed in total. Its streak of Le Mans victories between 2000 and 2005 was broken only in 2003 by the Bentley Speed 8, another race car fielded that year by Volkswagen Group. The petrol-powered Audi R8 race car was in 2006 replaced by the new Audi R10 TDI Diesel; however, the need to further develop the R10 meant that the R8 saw action in a few races leading up to the 24 Hours of Le Mans. History 1998: The challenge In 1997, sports car racing and especially the Le Mans 24 Hours was popular among factories such as BMW, Mercedes-Benz, Porsche, Toyota, Nissan Motors, and others. At that time, Audi Sport boss Wolfgang Ullrich started to evaluate the options of joining. With the upcoming American Le Mans Series also providing a stage for the US market, Audi announced plans in 1998 to compete in 1999, with the Audi R8R powered by a V8 turbo. As it was considered the better choice for a whole race due to less weight and wider tires, Audi ordered an open-top roadster from Dallara to be developed and run by Joest Racing. Yet, during the autumn of 1998, after the necessity of GT1 homologation was dropped in favour of LM-GTP prototypes, closed GT coupés like the Porsche 911 GT1, Mercedes-Benz CLK-GTR, and the Toyota GT-One proved successful. In response, Audi also ordered their newly acquired Norfolk-based Racing Technology Norfolk, led by Tony Southgate, to build a closed-cockpit car using the same drivetrain. The ACO rules for closed-top prototypes allowed cars to run with larger air restrictors, resulting in more power (about 600 hp), which resulted in a higher top speed in combination with the lower drag. To compensate this advantage over the duration of a race, the LMGTPs were limited to smaller tyres and smaller fuel tanks. 1999: The R8R and R8C Following a period of testing, two R8Rs debuted at the 1999 12 Hours of Sebring. The BMW V12 LMR won, which was a