Testament to Audi’s commitment towards pioneering new technologies, the brand with the four rings has unveiled its new 2012 Le Mans racing prototypes, which combine highly-efficient TDI diesel engines with hybrid technology and quattro all-wheel-drive. 

Audi first saw Le Mans victory back in 2001 with a TFSI engine, and followed this up in 2006 with a historic first win for a diesel powered car.

Now Audi is targeting yet another technical milestone in the world's most famous endurance race.

The automaker will be fielding four race cars in the 2012 FIA World Endurance Championship, which includes the famous 24 Hours of Le Mans in June. However, only two will be hybrids, with the other two relying mainly on lightweight technology.

The hybrid versions, labeled the R18 e-tron quattro, make their race debut on May 5 in the 6-hour race at Belgium’s Spa-Francorchamps and fight for overall victory at the famous 24 Hours of Le Mans on June 16 and 17.

These hybrid LMP1 racers feature what Audi calls its next generation quattro all-wheel-drive technology. Essentially, one axle is powered by an internal combustion engine in a conventional manner, and the second by electric motors. Interestingly, this also celebrates the return of the quattro name in racing, albeit in an entirely new form.

On the Audi R18 e-tron quattro, kinetic energy is recovered on the front axle during the braking phase. It is fed into a flywheel accumulator, where it can be stored until a boost in acceleration is required. During this procedure only the front axle is involed. The V-6 TDI powerplant producing 510 horsepower continues to transmit its power to the rear wheels. Both systems complement each other to create the new drive principle e-tron quattro, and both can work fully independently.

2012 Audi R18 e-tron quattro LMP1 race car

2012 Audi R18 e-tron quattro LMP1 race car

The other two race cars fielded by Audi will be R18 ultra LMP1s. These share a platform with the hybrid R18 duo, though are significantly lighter due to their lack of hybrid technology. Audi is convinced its TDI engines still have more potential without any assistance, which is why the automaker not only supports hybrids in motorsport as it does in production, but in parallel also the further development of the conventional drive.

The R18 e-tron quattro’s twin brother more than lives up to its R18 ultra model name--it is the lightest Le Mans prototype that Audi has ever built. To compensate for the additional weight of the hybrid system the subject of lightweight design and construction was the focus throughout development of the 2011 Le Mans race winning R18 TDI. In addition to the many detail optimizations there is also a genuine innovation in the transmission area. A new gearbox with a carbon fiber composite housing was developed for the R18s, a premiere for endurance racing.

A thorn in the side of Audi could prove to be Toyota, which is returning to endurance racing this year with its hybrid LMP1, the TS030 Hybrid. There may be a bit of a learning curve, however, as Toyota hasn't been directly involved in Le Mans since the 1990s.