In two weeks from now, the Audi R18 e-tron quattro will be challenged to claim its fourth consecutive victory in the Le Mans 24 Hours, with Audi competing against three manufacturers. At the same time, this will be a battle of the concepts: diesel vs. gasoline engines, kinetic vs. thermal energy recuperation and electromechanical vs. electrostatic vs. electrochemical storage. This brings back memories of the race two years ago.
