No fewer than 42 GT cars have been entered for this year’s 24 Hours of Spa, the celebrated Belgian endurance race which attracts huge crowds to Spa-Francorchamps whatever the weather. Indeed, the forecast is uncertain yet again for this weekend’s visit to the Belgian Ardennes.

And that’s what’s troubling Michelin’s technicians… With 38 partners entered for the 24 Hours of Spa, plus a further 24 for the FIA GT1 World Championship races, Michelin will be working with a total of 62 cars at Spa-Francorchamps where changeable conditions promise to make the weekend something of a brainteaser for Michelin’s men.

“We have around 7,000 tyres with us at Spa,” says Michelin technician Franck. “Those of our partners who are contesting the 24 Hours of Spa will only use customer competition tyres. They will have a choice of three types of slick (ranging from soft to hard: S7, S8 and S9) and one wet weather cover. We are not allowed to re-cut the tread patterns.”

The regulations restrict cars to five sets of tyres each for free practice, pre-qualifying, qualifying and the first two laps of the race. After that, there is no limit. And there is no upper cap on wet weather tyres either.

Thursday’s programme is particularly busy, with free practice starting at 9am, followed by pre-qualifying and three qualifying sessions that will take teams up to 11:30pm.

24 heures de Spa, Michelin, Tire