Thundering down the long Mulsanne Straight at more than 240kph in the dark, with the car squirming on rainsoaked asphalt and the headlights searching through a murky wall of spray, is no place for the faint-hearted.

Allan McNish, two times Le Mans 24 Hours winner and a strong contender in the number two Audi when the sportscar classic celebrates its 90th anniversary next week, is more of a braveheart.

The Scot, a former Formula One driver whose ex-Toyota team mates are Audi's big rivals, walked away from a spectacular crash at the Circuit de la Sarthe in 2011 and has no hesitation in coming back for more.

"If there's something lurking in the back of your mind, you stop racing and you do something else and you get a desk job. It's that simple," he told Reuters in a telephone interview from his Monaco home.

"If your inner instinct says you don't want to drive down a circuit at an average speed of 150mph in the middle of the night then you don't do it.

"My inner instinct says that there's another Le Mans race victory that's up for grabs and a world championship at the end of the year and that's what I'm focusing on doing," added the 43-year-old.

McNish is partnering Denmark's eight-times winner Tom Kristensen and Frenchman Loic Duval in the number two factory Audi R18 e-tron quattro. The trio were fastest in last weekend's eight hours of testing.

TOYOTA THREAT

Audi have won Le Mans 11 times in the last 13 years but McNish's most recent victory was with Kristensen and now-retired Italian Rinaldo 'Dindo' Capello in 2008.

The Scot was second last year after hitting the barriers three hours from the end. In 2011, he walked away from a massive impact after contact with a much slower Ferrari in the first hour sent his Audi flying into the barriers, where it disintegrated.

Toyota are again the main threat with their hybrid car and McNish expected them to be in contention all the way after making a strong return in 2012 following a 13-year absence.

"I don't think we necessarily saw their pure performance at the races so far this year and certainly we didn't see it at the weekend," he said.

"I would say we've got to be keeping an eye on the upper end of the pitlane to see what those characters are up to.

"Obviously I know the people there... I know the team and I hope they have a fantastic race and finish a very fine third or fourth behind the Audis," added the Scot. "There's no question they will be good, they will be taking the fight to us."

Lapping slower cars is an occupational hazard at Le Mans, where sleek LMP1 prototypes mingle with regular sportscars and fatigue can dull reactions. McNish hoped for a dry race.

"Physically Le Mans isn't demanding because you've got such long straights," he said. "But when you are going down the Mulsanne at 210 and the car's aquaplaning underneath you... you do naturally tense up on the steering wheel, you are naturally on the edge of your wits all of the time.

"A wet race, and just driving generally in the wet around there, is significantly mentally and physically more tiring than in the dry.

"From a driving point of view, I prefer a dry race just purely because I think we're in pretty good shape in the dry. In the wet you can't control whether the guy spins in front of you. You can't in the dry either but you've got more chance of it happening in the wet."

SLEEPING HABITS

With qualifying scheduled for next Thursday, McNish's immediate priority is to stock up on rest. He stays at home, preparing for a weekend when sleep is sporadic at best.

"I am very fortunate, I can sleep anywhere any time," said McNish. "But it's very easy to get caught up in the race. This is Le Mans.

"As a driver at my first time in it, as soon as I got out of the car I wanted to know what was happening, I was watching the data, I was looking at the lap times, I was living it as if I was still driving the car.

"So physically, I wasn't driving but mentally I was. And it was absolutely exhausting. With experience, you realize you can't do that. So you do tend to have your switch-off point and you can get away from it and try to conserve a bit of energy."

Audi will have four specially equipped containers right behind the pits for the drivers to sleep and shower in as well as having doctors, physios and dieticians on hand. That much is under control. The rest can be in the lap of the gods.

"Motor racing is always that risk and reward. There is always the chance that it can go wrong with a technical failure or an accident," said McNish. "It's a 24 hour race, it's like a grand prix season in a day."

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