BMW caught out by balance problems

Both drivers expressed their surprise with the handling of their cars at the start of the day in Bahrain, but they felt more comfortable by the end of the afternoon session.

"The second session was better, but we still have balance problems," said Kubica, who was third fastest in the afternoon session after he switched to the spare car.

"We used the spare car in the afternoon because in the morning I experienced the same problems we faced in Malaysia," he added.

"This one is more consistent so now we have to analyse why this happens. The car's setup is still not perfect, but it's not looking bad."

Heidfeld was slightly slower than his teammate, and the German was also mystified by the handling of his car in comparison to the pre-season test at the track.

"To begin with the car's balance was not exactly how it was in the test here six weeks ago," he said.

"We had to look into why we had oversteer, but we worked on that and I am quite happy."

The team are expecting the track conditions to improve over the course of the weekend, as more rubber does down on the dusty track surface.