Sebastian Vettel and Mark Webber hit out at the state of the tyres after second practice for the Malaysian Grand Prix.
Vettel was second fastest in Sepang, with Webber sixth, but both drivers fear the weekend is revolving solely around tyres.
"It looked pretty OK but quite a mess if you look at how long the tyres last," Vettel told Autosport.
"It doesn't look very nice I would say. I hope we have enough tyres to survive the race. It is not a lot of fun and that is how it is."
The RB9 was comfortably quickest over one lap in Australia but slipped back in the race, behind Lotus and Ferrari.
"The whole category is geared around tyres at the moment," said Webber. "Everything is around tyres. Tyres, tyres, tyres, tyres, tyres..."