Audi boss says economy will be key

Pescarolo Sport driver Franck Montagny set a blisteringly quick time around the Le Sarthe circuit in last weekend's official free practice session, beating the fastest time set by Dindo Capello in the new diesel-powered Audi R10 TDI by nearly two seconds.

Speaking to autosport.com, Ullrich admitted he accepts that their new car does not have an advantage over Pescarolo in terms of pace, but all other things being equal, he reckons they have the edge when it comes to fuel economy and ability to last longer on a tank of petrol and stop less.

"It will be a tough and hard competition. We are on really on a very similar level with the Pescarolo cars," Ullrich said in the interview. "We will be very similar [in terms of pace]. We should have the chance to use the better fuel economy of the diesel car and then it is a question of unpredictable pitstop and driver errors, and strategy.

"I'm not going to tell you how many laps we are going to do! That is part of the strategy!  But I think we expect a gain of about eight or nine per cent in fuel economy and that is roughly that's where we think we will be.

"This is what we had already achieved with the R8 because of the FSI technology. If you look at what we could do last year with the FSI car which was one to two laps more than the Pescarolo car which had ten litres less fuel capacity.

"This is the point - if you can do less pitstops you have at least the advantage of gaining some time. I don't know exactly how much time - we are just calculating how much a pitstop will take but it is for sure more than a minute that we will lose each stop.

"This was the point from the beginning and why we have decided to go for a diesel. We wanted to prove what diesel technology can achieve. In principle because of the diesel technology for the same power output, as you can see on your road car, it uses less fuel. So this is something we want to use for the race for sure."

However, despite the advantage Ullrich believes the team have in terms of fuel economy, he admits that reliability could still decide the race.

"If our performance remains how we have seen it in the pre-test, then if we have a technical problem and the other car has no technical problem then we can't win the race," he added.

"Our target was to go to Le Mans and be in the position to be able to win the race. We have seen that the performance is there and the rest is in the hands of the team at the weekend and the mechanical reliability."