Kubica happy with BMW's step forward

BMW Sauber has brought a raft of upgrades, including a new floor and engine cover, designed to improve the aerodynamic characteristics of the F1.09, and the Pole reckons that the team has made the car faster by two to three tenths of a second per lap.

"It's difficult to judge, but we saw more or less what we were expecting," said Kubica when asked by AUTOSPORT for his impressions of the improvements. "It was around two or three tenths improvement.

"But on this track, our car has less problems than on others. We have lots of problems with long corners and here they are short, sharp corners, so the car is struggling less."

Kubica was disappointed not to be starting on row four, blaming a small mistake and traffic during the Q3 session for leaving him 10th.

"It was a tight qualifying with a lot of cars very close together," said Kubica. "We managed to get into Q3, which was good, but unfortunately we didn't manage a good lap time on the first lap due to a small mistake. On the second lap, I had traffic. That cost me two positions.

"Once you go into Q3, tenth is the worst because you waste your tyres and you have a fixed strategy. In our case, it would have been better to miss out!"

Kubica also backed BMW Sauber's decision to abandon KERS earlier in the season, despite McLaren-Mercedes having won the Hungarian Grand Prix and locked out the front row in Valencia.

"This topic was closed for myself from the beginning because I was never in the position to run KERS [because of weight]," said Kubica. "But not all KERS systems are the same.

"McLaren went well from the start of the season, and we spent a lot of time over the winter to get it to work. On some occasions, it worked well, on some it worked less.

"That's why the team decided to drop KERS and concentrate on the aerodynamic development because for us it was a big compromise to run it aerodynamically."