Audi fastest in practice at Le Mans

The session was hit by rain just over 60 minutes into the six-hours, so there were no improvements to the front running times for the vast majority of practice. The fastest times were set after each car had completed just a handful of installation laps, before they were forced into wet weather testing for the rest of the evening.

Last year's winning crew of Allan McNish, Tom Kristensen and Rinaldo Capello posted the quickest time of the session, but just half a tenth quicker than their team-mates Lucas Luhr, Mike Rockenfeller and Marco Werner in the #2 R15.

The #9 car of Marc Gene, David Brabham and Alexander Wurz was the quickest of the Peugeots but also suffered the brunt of the team's problems, requiring a new clutch mid-way through the session before returning to the pits in a cloud of smoke in the final 10 minutes.

Peugeot showed good wet weather pace though, with Sebastien Bourdais lapping up to five seconds a lap faster than anyone else on the circuit during his wet stint in the #8 908.

The Pescarolo-run customer Peugeot 908 of Jean-Christophe Boullion, Simon Pagenaud and Benoit Treluyer was the fourth fastest car in the session, outpacing two of the factory cars.

The best of the Lola Aston Martins - the #008 car of Darren Turner, Anthony Davidson and Jos Verstappen - finished the session eighth overall, five seconds off the pace of the lead Audis.

The second Aston Martin Racing car was less than a second behind, while the #009 car was a couple of seconds behind and had to be pushed back to the garage when it ground to a halt while leaving the pits near the end of the session.

The Team Essex Porsche RS Spyder was quickest of the LMP2 cars, 1.5 seconds ahead of its nearest rival, the similar car of Team Goh.

The factory Corvettes led the GT1 class with the #63 car of Jan Magnussen, Johnny O'Connell and Antonio Garcia a couple of seconds faster than the #64 example of Oliver Gavin, Olivier Beretta and Marcel Fassler.

GT2 was headed by the Team Felbermayr Porsche of Richard Lietz, Marc Lieb and Wolf Henzler.

Three cars failed to complete a significant amount of meaningful running in the six-hour session. The LMP2 Barazi Epsilon Zytek stopped with an oil system failure after completing only 12 laps. The #68 JLOC Lamborghini Murcielago stopped on its outlap with a broken driveshaft. The #41 GAC Zytek completed just 16 laps before a broken input shaft curtailed its evening's running.

There were several spins and trips across the gravel during the evening but the only accident befell Jean de Pourtales, who crashed the #39 Kruse Shiller Lola-Mazda into the wall at the Ford chicane.