Over the course of the race weekend, we noted a marked difference between the sound of the R15 at speed and other cars on the track. GT1 Corvettes sound like proper American sports cars, complete with a thunderous V-8 exhaust note. The GT2 Ferrari 430 GTs scream by with a high-pitched Italian wail. Curiously, the 600+ hp Audis streak past, making almost no noise at all.
This, says Ullrich, is a sign of the R15's efficiency. "Some people have the imagination that a race car should be loud, but that noise is wasted energy. The turbochargers capture the maximum amount of energy coming out of the exhaust and put it to use." Even the exhaust is put to good use - the tips exit out the top of the engine compartment, and are directed at the rear wing to generate additional downforce.
We didn't have a chance to pilot this new, multi-million dollar racer ourselves, but we asked Allan McNish - the man partly responsible for bringing home the R15's first race victory - what it was like.
"It's a whole new ballgame," he said. "It's much more on its toes compared to the R10. The R15 is more refined, not as much as a beast. I can do a lot more with it because the balance is so much better."
Audi may expect McNish and his teammates to do much more come June, when the team enters the 24 Hours of Le Mans. 2009 marks Peugeot's second year at Le Mans, and the French diesels ran quite strong last season. We're betting they'll have something to say about Audi's continued dominance in the LMP1 class.
We expect to witness a battle royale in the French countryside this summer - we just don't expect to hear it coming.