This is a pretty well done animation showing how some of the systems work on the Audi R18 e-tron Quattro diesel hybrid that won this year’s 24 hours of Le Mans. It uses the next iteration of the electromagnetic flywheel energy storage system that was first pioneered on the Porsche 911 GT3 RS Hybrid endurance racer. The energy from the regenerative braking is used to spin a flywheel up to 40,000 rpm in a vacuum. The Le Mans rules only allowed the team to power one of the axles with the electric motors. In the R18, a diesel engine powers the rear wheels and the electric motors drive the front wheels during boost mode.