Webber Confident of More Speed

The Australian could only manage 15th and 16th fastest in the two sessions as a new aerodynamic package fitted to the Williams did not appear to have transformed the pace of the car as had been hoped.

Speaking after the session Webber said he was hopeful of better fortunes on Saturday - and said the team were well aware it was not quick enough.

"We have worked hard in both sessions in terms to get more out of the car because we have to find some more pace, no question about it," said Webber.

"We've done some work with Michelin too to pick the right tyre, which are both working well. We will go through our data tonight and I am sure the engineers will do a good job and we'll come back with a better pace tomorrow."

Heidfeld, whose afternoon running was affected by a radio problem, was 10th and 17th fastest in the two practice sessions but not too disheartened by the lack of speed.

"The only true problem we had today was that we had to change the radio in the second session. We had to do a small compromise on our planned schedule, changing it a bit around," he explained. "Still, overall it was a good day in terms of what we managed to do."