Audi Sport Team Joest’s test entry in the 1000-mile “Petit Le Mans” race at Road Atlanta (U.S. state of Georgia) had an unexpected outcome: The American endurance classic had to be red flagged just before half-time due to torrential rainfall. Although Audi had led almost entirely, the two R15 TDI prototypes were only classified in third and fourth positions. Small consolation: The Diesel-powered racing car won the efficiency award “Michelin GreenX Challenge” – a trophy awarded to the most environmentally friendly car.

The technically innovative Audi R15 TDI had also been the fastest car on race day. At the start in wet conditions, Allan McNish and Marco Werner immediately passed the two Peugeot 908s which started from the front row of the grid, pulling further and further away from their competitors. Then on a drying track, the superiority of the R15 TDI was even more impressive: Only a caution period prevented Allan McNish putting the second of the two Peugeots a lap down after one and a half hours.

In the following hours, drizzle and a total of seven caution periods ensured that the leaders stayed close together. Despite this, Allan McNish and Dindo Capello kept the lead for more than four hours before McNish spun behind the Safety Car on the extremely slippery track at the start of the fifth hour dropping behind the two Peugeot 908s.

When heavy rain started shortly afterwards, Audi Sport Team Joest was quick to react and brought the two R15 TDI cars into the pits for a change to rain tires a lap earlier than the competition from Peugeot. The rain, however, became so torrential that more and more cars spun off the track due to aquaplaning, including the two Audi R15 TDI cars.

When the prototypes could not even follow the Safety Car anymore, the race was red flagged after 4h52m of the scheduled 10 hours. At this point, the two Peugeot 908s were running slightly ahead of the two Audi R15 TDI cars. As the weather did not improve, the race was not re-started with Peugeot declared the winners although less than half of the distance had been completed.

For safety reasons, Audi also voted not to re-start the race although the two Audi R15 TDI cars would have been hard to beat on this day – a positive feeling with a view regarding Le Mans 2010.

Source : Audi North of America