Heidfeld downplays BMW's slow start

Both Heidfeld and team-mate Robert Kubica finished near the bottom of the times, with the Germany 2.2 seconds off the pace after 37 laps.

Heidfeld ran without a KERS device fitted to his car in the afternoon session, in order to decide if he will continue to use it during the weekend.

"Certainly the results don't look good, but in Melbourne it was a similar picture on Friday," Heidfeld said. "Nevertheless we do have some work to do in order to improve the balance of the car. In the first session I was running with the KERS and in the second I didn't use the device.

"Using it makes a huge difference to the car's balance, but without it there is the loss of the boost. This was the experience we wanted and why we took it out for this session.

"Now we will throw everything into the mix - laptimes, data and my feelings - and then decide whether or not to use the KERS here."

Kubica said the team had exclusively focused on preparing for the race, which may explain why he finished down in 17th place.

"Today we concentrated totally on race preparation, and particularly on tyre comparisons," said Kubica. "The specifications that Bridgestone have brought to Malaysia are very different from the ones we used in Melbourne, and obviously Sepang also has different characteristics.

"In addition, the track temperatures were much higher here, so it was a new situation. We gathered a lot of data and have the basis to use the tyres to their full potential during the race. While we were doing long-runs today, tomorrow we will focus on the single lap performance."