High Quality Content by WIKIPEDIA articles! The Audi R15 TDI, commonly abbreviated to the R15, is a Le Mans Prototype (LMP) racing car constructed by the German car manufacturer Audi AG. It is the successor to the Audi R10 TDI. Like its predecessor, the R15 TDI uses a turbocharged diesel engine, although the R15`s V10 engine is physically smaller than the R10`s V12. The smaller engine is pushed further toward the middle of the car than in the R10, resulting in a more neutral weight balance that gives the car better agility around the corners than its predecessor.