Rosberg encouraged by practice showing

The German driver enjoyed a strong day, posting the fourth quickest time in the afternoon session.

Rosberg reckons there is still room for improvement, and the Williams driver admitted the tyre choice will be crucial this weekend.

"We are a bit higher up on the time sheet than we usually are on a Friday, which is a positive sign," said Rosberg.

"Tyres are important this weekend and it's going to be difficult to make the right choice.

"We worked hard today and discovered some useful things and I think we now have a good idea which set-up direction to take. I am pretty pleased with our progress, obviously we can still improve, but we're heading in the right direction."

Teammate Alex Wurz lost valuable track time in the morning session following an electrical problem. In the afternoon he was 12th fastest.

"I lost some time in the morning due to an electrical problem which meant I couldn't run through a few of the set-up items I had planned and had to play catch up in the second session," he said.

"The afternoon was actually quite messy, there was lots of traffic and I was only really happy with my last long run. It felt strong, but I couldn't get the best out of the car today. I hope to find a good rhythm tomorrow in order to extract the best I can out of qualifying."