Test programme begins for Jag

The Cosworth-powered car was taken from the stage where it was unveiled and was then unleashed on to the track. Its first day didn't quite go to plan, however, and the car returned to the pits after a lap on the back of a truck following a gearbox problem.

After a break of a couple of hours, while the problem was rectified, Webber put in another five laps, including a couple of tours wearing Christian Klien's helmet for filming purposes.

"We have concentrated on understanding the issues with the R4, and the big thing in F1 is to be self-critical," said Webber before going out on track. "We have understood what happened, and taken that knowledge into the R5.

"It's going to be a big challenge for us to stay in touch with those we upset last year. But if we can just nip away and improve on what we did last year and finish in the points a bit more regularly, I think we'll have done a great job."