Despite facing the sternest challenge yet of their R10 TDi's unbeaten run, Audi yet again prevailed in the final round of the American Le Mans Series at Laguna Seca, Allan McNish and Dindo Capello lauding their car's superior fuel economy as the reason for their win.

Having already wrapped up the drivers' and teams' titles well in advance of the season finale, Audi were nonetheless facing a challenge in extending their seven-race winning streak since the pioneering R10 was introduced back at the Sebring 12 Hours, particularly after qualifying when they were ousted by the visiting ?European' competitors of Zytek and Creation, as well as the continue threat from Penske Porsche and Dyson.

Nonetheless, the difference on the day was a long final stint by McNish, made possible by the excellent frugality of the R10, with the Scot driving for well over a quarter of the race on a single tank of fuel and set of tyres to cross the line as the comfortable winner from team-mates Frank Biela and Emauele Pirro.

"There is no way we could have made that number of laps without the diesel," McNish said. "The team gave me all the info I required in terms of distances required to make sure we could get to the end. I'll tell you it was right at the limit."

Still, it was a typically close race, with six cars on the lead lap over the first three hours. However, as mistakes began to creep in, the peerless Audis pushed forward, to win from the Creation of Nicolas Minassian and Harold Primat, while the pole sitting Zytek of Stefan Johansson and Johnny Mowlem hit problems through the race, eventually ending it off the course two laps down.

Fourth and fifth fell to the Penske Porsches of Lucas Luhr and Romain Dumas, followed by Sascha Maassen and Timo Bernhard, a result that means Luhr and Maassen will actually share the LMP2 drivers' crown. Interestingly, it was a perfect outcome for the former co-drivers who were split up in the team's determination to have at least one driver claim the title.

"Our perspective was to be safe and be sure we finished," Maassen said. "We wanted to make sure Porsche would have at least one driver champion. Our strategy was thought out well. Even if you plan so many things, sometimes they don't work.

"The plan to finish when we were separated was not Roger (Penske's) plan; it was our plan," Maassen added. "He's a racer and the thing is he sees chances to win overall. Even with smaller car he tries everything. I saw Lucas pushing really hard but I was concerned that something big would happen. It was great to see. I hope we can do something similar next year."

Indeed, Luhr had been pushing for victory in the latter stages of the race, rapidly catching McNish before spinning away any hopes of challenging for the lead, dropping a couple of places and adopting a conservative strategy thereafter.