Oct.2 (GMM) Mark Webber has pointed to Pirelli's 2013 tyres as the reason for his struggle against dominant teammate Sebastian Vettel this year.
The Australian, who is heading to Le Mans with Porsche next year, fought Vettel hard for the title in 2010, but the German utterly dominated in 2011.
"In 2011 I was only behind Sebastian in qualifying," Webber told Germany's Auto Motor und Sport.
"It was clearly something to do with the fact that his driving style was better suited to the car.
"In the race, we were pretty much the same -- I got a lot of fastest laps," he added.
In 2013, however, Vettel has been dominating again.
Again, Webber points to the tyres. "They are not always easy to understand," he said. "You lose a lot of time if you don't bring them into the right working window."
Referring to Singapore, where Vettel's dominance moved into an even higher gear, Webber said: "On the medium tyres, I had a good balance. I was able to get the very best out of them.
"But as soon as we went onto the softer ones, it was very difficult to drive."