D: The race is so long in time, and over such a long distance. Do you think it's the attention to detail that plays a vital part in winning?
TK: The detail is very important. A little bit of imbalance in the brake temperature can be crucial later in the race and will also influence the tyre pressure. You have to keep your eye on everything and do your preparation properly. That's really important, especially now that Le Mans is so fast.
D: Engine capacities have been getting smaller over the years. However, the car balance and how it sits on the road appears to be improving greatly. Is how the cars are being put together helping the speeds to stay high?
TK: This year the reduction in the engine size led us [Audi R18] to downsize from a V10 to a V6 engine. While this meant less power it did give us more agility, more room for better aerodynamics and less weight in general. Audi has really focused on getting the weight down. We now have a closed car to make it more efficient through the air, especially on the straights. We have electric gear change now and other things that make the weight distribution in the car much better. It's really fast and agile in the corners now. The top speeds are little bit slower but not that much and the time to get to top speed is much faster. There's not much difference in the lap times.
D: You don't really get a chance to test for Le Mans so that must make it a bit interesting, especially with a new car?
TK: There was a test day this year that benefited us, and of course the rest of the teams. But that was still a month before the race. With a year between each Le Mans, it is a challenge, particularly this year with the regulation changes.
D: Is it possible to explain what Le Mans is like to mere mortals who will never get to experience the place, or the speeds?
TK: Le Mans takes the best out of everyone. Winning is important but it's not everything. It's such a big and great event in motorsport. You do more kilometres in that one race than Formula One do in a season, and probably a higher average speed. We average about 220km/h including pit stops and cover nearly 5000km. The fans are really passionate about endurance racing and know their stuff.
For me it started when I watched the movie Le Mans when I was young. In 2008 they did a documentary on us winning, and while the racing might have changed the passion was still very much evident. Part of it is the simple concept of driving as far as you can over 24 hours.
The trick at Le Mans is to get the car "in the window". Everything is critical: the tyre pressure, the brake temperature, and that means you have to push the car a lot to get it into the window - it's about getting everything to work right and getting the car to flow through the corners. For example, you can go 325km/h into the Porsche Corner and go down to fifth gear and let the car flow into the corner. There are a few bumps there that unsettle the thing, but when you trust in the steering and the G-forces start to work it's very physical. Keeping it in the window means everything is working properly. Keeping it on the track is also very important.
D: You've covered so many kilometres and races around Le Mans over the years - do you dream about the place?
TK: Maybe in the beginning, but not now. It's more trying to visualise the race, especially the traffic, and how to get through it, especially at night. That's probably the hardest mental challenge in a race car.
D: Are you going to try to get 10 wins?
TK: It's not really about the number of wins. Of course you want to win, but after so many years with Audi it's about winning with them. Personally I need to win and I'm disappointed we didn't go far this year at Le Mans. But, on the other hand, I'm extremely pleased an Audi won because that is what makes the team spirit so good. We have developed the car together so we win together and lose together.
A long day's journey into night - and back again
The Le Mans 24-hour race is the world's oldest sports car endurance event. The race was first held in 1923, when it was known as the Grand Prix of Endurance and Efficiency.
Originally it was for cars sold to the public, but morphed into an event for purpose-built race cars - the Prototype class - and the Grand Touring class, loosely based on high-performance sports cars available to the public.
The race is organised by the Automobile Club de l'Ouest on the Circuit de la Sarthe, a mix of public roads and racetrack.
The race has inspired other 24-hour events including Nurburgring, Daytona, Sebring, Bathurst and Spa-Francorchamps.
Le Man is part of the Triple Crown of Motorsport with the Indianapolis 500 and the Monaco Formula One Grand Prix.
Between 1925 and 1969, the race started with drivers running across the track, leaping into the car, buckling rudimentary seatbelts, firing up the engine and roaring away.
These days all the driving crews line up opposite the cars, which are in start order. The driver nominated for the first stint will be in full race attire with his two teammates in overalls next to him.
After the Go signal, the crew cross the track and have seven minutes to get the start driver into the car.
The clerk of the course waves away each successive car. When they're all up and running on the formation lap, the green flag falls for a flying start.
