Drivers prepare for a tough race

The surface of the Sentul circuit started to break up during practice and qualifying this morning, and persistent storms are making the track increasingly dirty.

Changeable weather has made predicting the conditions impossible as the half-hour qualifying was twice dry enough for slicks but was also twice rainy enough to call for wets.

Series leader Romain Grosjean, who will start fourth after a spin on slicks on a damp track in qualifying, is expecting a difficult time in the weekend's two races.

"The track is breaking up under us and there are stones and chunks of debris flying up at you," he said. "The cars are getting damaged and it's so dirty that you can't see a thing."

The teams have reinforced fragile aerodynamic devices such as the wings and bargeboards with aluminium to protect them from being damaged by the debris, but they are still struggling to prepare for the conditions.

"I have no idea what to expect," said Grosjean. "It's probably going to be wet and dry, and visibility will be very poor again."

Pole-sitter Vitaly Petrov will have the best of the conditions, but he too is expecting changeable weather.

"It's changing every 20 minutes," said the Russian. "If it stays one way or the other we are OK, but we're having to change again and again. I dare not think how many times we will have to stop for tyres in a 75-minute race."

Luca Filippi, who starts today's race along Petrov on the front row, added: "There is so much dirt here that if you follow another car you can't see anything, even when the rain is not bad. You have to wipe your visor with your sleeve every 30 seconds!"