Kubica urges BMW to improve quickly

Despite showing strong form in the first two races of the season - Kubica was set for at least second place in Australia before a clash with Sebastian Vettel and Nick Heidfeld was runner-up in Malaysia two weeks ago - the Pole believes the team has been overtaken by many of its rivals.

"It will have to be really big (package) if we want to be at the top because the gap is quite big," said Kubica when asked by AUTOSPORT if he expects car improvements for next week's Bahrain Grand Prix.

"Some of the teams have moved forward and some of the teams are already, after the decision of the FIA, adjusting their cars to the clear idea of the regulations. We have exactly the same car that we had in Australia.

"The gap to the front cars is pretty much the same; the difference is now Toro Rosso, Renault and McLaren are stronger.

"If we don't bring anything new [to Bahrain] we can struggle as well there, although in Bahrain the gaps will be smaller because downforce is not as important. Braking stability and traction is more important, but the overall picture will not change."

Despite admitting to making a small mistake on his best Q1 lap, Kubica believes that the qualifying pace of the BMW Saubers is representative of their competitiveness in China.

"Today is not idea, unfortunately it didn't work out," he said. "The pace of the car and the way we approached qualifying has been a bit disappointing.

"Anyway, I would not be much further forward even without the small mistake. So that's how it is."

Kubica also believes that his inability to run with KERS, which he tried in Friday practice but discarded today, is partly down to how sensitive the BMW Sauber F1.09 is to weight distribution in comparison to some of the other teams on the grid.

"There are some drivers that have no problem with it that don't weigh much less than me," said Kubica. "It looks like our car is very sensitive to weight distribution and it's very important not only for the car balance, but the setup as well.

"In the past, we were playing quite a lot with it, and for now the situation is like this. For the future, I don't know."