Audi has announced that Allan McNish has retired from top-line sports car racing with immediate effect.

Listen to McNish explaining his decision below:

The news makes Allan’s guest editor-ship of the January issue of Motor Sport all the more special, given that it was one of his last acts as an Audi prototype driver. He’ll remain with the manufacturer and will be ‘heavily involved in 2014’, fittingly, as the one word he used to describe Audi in the magazine was “home”.

Damien Smith’s Texas road trip with the three-time Le Mans winner yielded some quotes which might throw a different light on the decision.

Talking about the effort required to drive modern prototypes on the limit, McNish estimated that he put around 80 kilos of force through the brake pedal, “four times a lap around Austin. That’s quite a lot. That’s why I got out after the one stint yesterday.

“I’m 43, and I don’t think there’s any question I’ve still got pace. There are two things that are the limiting factor in a driver’s career: one of them is the physical side – are you fit enough? Are your eyes good enough? And the other one is do you have the passion to be able to do it, to be able to keep up with the guys coming through?

“Now, if you look at the weekend just gone or the last stint at Silverstone earlier this year, or the first lap in Brazil, I don’t have much problem with that. But there will come a day… that will be the right time to give the other guys the reins.

“I’m not going to continue to race for the hell of it. I won’t be racing in five years time, I can tell you that. But you have to have something else that replaces the energy that you put into driving, and something else you enjoy too. Because I’ve had 30 years of a hell of a lot of fun.”

One thing’s for sure: McNish will be missed at the sharp end of the WEC grid. It’s a shame that he won’t get to take the fight to Porsche next year, but he’s had a great career, with 17 years at the forefront of his profession, three Le Mans wins, three ALMS titles and a World Championship to cap it off.

As he said in the magazine, “the positives outweigh everything else”.

Click here to listen to our podcast with Allan McNish