Audi drivers cautious about race speed

"For sure the Bentley will be quicker on race lap times," said Audi UK driver Biela. "The gap will be closer than in qualifying, maybe just one second. The pole was much more important to them than it was to us privateer Audi teams."

Champion Racing team driver Pirro agrees: "Our car is not the favourite, and on paper Bentley should win. But if they make mistakes, we'll be close enough to bite their tails. We've got proven reliability and we know how quickly problems can be fixed on the R8."

Fuel mileage remains an unknown just hours before the race. Most believe that the Audis should run longer than the Bentleys, an advantage that might add up to a very close fight overall.

"Last year we were getting twelve laps to a tank," says Biela. "This year we have less power with the new regulations, so we should be able to go further. But we won't know until after a couple of stints."

Bentley's Tom Kristensen, who won the event in an Audi with Biela and Pirro for the last three years, is sure the Bentley won't be able to run as long as the Audi: "We know we have higher fuel consumption. We've got to be faster on the track."

With rain falling heavily four hours before the start, the weather may also play into the hands of the Audis, who have proven ability in the wet.