Formula One tyre supplier Pirelli has warned teams against gambling on using wet tyres for long on a drying track at this weekend's Malaysian Grand Prix, as the rubber will blister and degrade very quickly.
The high probability of a wet qualifying session or race is a cause of concern for F1 teams, as very little testing has been done on new tyre supplier Pirelli's wet and intermediate tyres ahead of the season.
Should there be rain and the track gradually dry, many teams may gamble by staying out on wets before switching directly to slick tyres, thereby skipping an extra pitstop to put on intermediates, but Pirelli motorsport chief Paul Hembery said Friday that such a move would likely backfire.
"I hope they have to go through rain-intermediate-slick and they don't just jump from rain," Hembery said. "I don't believe they will be able to do rain to slick, because the rain tyre is very much a rain tyre and doesn't operate well on drying tracks and will blister very quickly."
"You don't want to be on a dry track with the full wets."
Comparing the Pirelli tyres to last year's Bridgestones, Hembery said the Pirelli intermediate is closer to a slick than the Bridgestone was, but the rain tyre is even more of a pronounced wet-weather tyre than that of its predecessor.
He could not give an accurate forecast of how long the wets or intermediates will last, due both to the lack of preseason wet testing and also because it was impossible to simulate the effect of a full field of F1 cars and how quickly they will create a dry racing line.
"I have to admit to some inexperience in that sense, because we don't know the effect of 24 cars drying the track," Hembery said. "It can have a very huge effect and that's something we will only see when it happens."
Despite the unknown quantity of a wet race, Pirelli was not merely crossing its fingers and hoping for the best.
"Hope doesn't come into it," Hembery said. "We've done a lot of testing. You have to be confident in your data, in your results. That doesn't mean you're not going to have surprises, because you do get surprises in this game."
Wet or dry, the Sepang circuit creates a major challenge for Pirelli. Unlike the unique street circuit of the season opener in Australia, the Malaysian race and its tropical heat will cause degradation in the tyres.
"We have to be realistic, its a challenge, of course it is," Hembery said. "Its a very hot, fast circuit, strange surface. Its probably our biggest challenge, but I might say its (the teams') biggest challenge because they've got the same learning curve to go through."