Vettel's tire fears

Formula One world champion Sebastian Vettel warned disintegrating tires could ruin his Malaysian Grand Prix after some worrying signs during free practice on Friday.

Vettel, gunning for his fourth straight world title, said he didn't know if Red Bull would be able to stick to its planned pit-stop strategy after his tires quickly fell apart on the Sepang circuit.

"I don't know how they could do this," fumed the 25-year-old. "I hope we have enough tires to survive the race.