Once again, for 2011, Audi took on a leading role in the LMP1 endurance class, presenting the R18 Ultra. For the first time since the days of the R8C (1999), Audi was putting a covered prototype on the track, with a closed cockpit. The reduction in engine displacements imposed by the technical regulations had made it clear that a simple update of the 2010 R15 would not have been enough. The engine was still a direct injection turbodiesel, but with a displacement reduced to 3700cc and a 120° V6 architecture, which allowed the center of gravity to be lowered. The chassis was built in one piece. The car proved to be very competitive and allowed Audi to beat Peugeot in the hard-fought 2011 edition of the Le Mans 24 Hours.