The United States Grand Prix meeting has been thrown into confusion and turmoil after Michelin decided to withdraw an entire batch of its tyres that it ran in Friday’s practice sessions from further use.
The French manufacturer has taken this extraordinary step after being unable to diagnose the cause of Ralf Schumacher’s tyre-related crash yesterday afternoon, one of several failures to strike the Michelin runners.
Michelin is urgently seeking to fly in brand new tyres of a different specification from its Clermont-Ferrand headquarters, and is in discussions with the sport’s governing body the FIA about scenarios whereby it could continue to compete in the weekend's events.
Using brand new tyres would necessitate special dispensation from the FIA as under current F1 regulations tyres have to be nominated prior to the race weekend.
It is also likely to require the unanimous agreement of all 10 teams, including the three rival Bridgestone outfits.
In the meantime Michelin advised its teams to make set-up changes that would give them a bigger safety margin for Saturday morning's free practice sessions.
A statement from Michelin read: “Following the incidents of yesterday, Michelin has controlled all the tyres that ran during the sessions of yesterday morning and afternoon.
“Despite all the checks that we’ve done, both here and in our test facilities in Clermont-Ferrand, we have not been able to understand or reproduce the problem of yesterday.
“We have explained the situation to our partners and to the FIA, and we have advised on the conditions for tests, qualifying and for the race tomorrow.
“These decisions have been taken in the interests of the safety of the drivers.
“We’ve been working with our people in Clermont-Ferrand in order to identify a product that we know is also capable of running at Indianapolis.
“We are in the process of discussing this possibility with the FIA, and are actively pursuing the dispatch of these tyres to Indianapolis.”