Mark Webber reckons there are still areas where Red Bull can improve, even though he ended day one in Japan with the top time.

Webber posted the third fastest time this morning in opening practice at Suzuka, 0.349 seconds off Jenson Button and 0.116 seconds slower than Lewis Hamilton. However in second practice the Aussie turned the tables on the two McLarens, posting a 1 minute 32.493 second lap, which left him 0.214 seconds up on Hamilton, who was 'best of the rest'.

"It was a nice change to get some good weather; it's been the first dry weekend for a while. We have plenty to go through this evening, it was a smooth one for us today and we completed all the runs we wanted to," he remarked. "It's a challenging venue in terms of balance here, but the car ran well and we tested both tyres.

"We have areas where we can improve, mostly with the balance, so we have some work to do. Suzuka is a great track that's remained untouched for a long time, it's a classic."

Team-mate Sebastian Vettel meanwhile was a lowly 17th in FP1, but improved in the afternoon, setting the third best time - a 1m 32.836 seconds, which left him 0.343 seconds off the sister car.

"The car's performing, but there are still some things we can improve," Vettel added. "It was a bit nervous this morning, better this afternoon, but we need to make a step overnight. I think tomorrow will be very, very close, so everything we can get out of the car will matter.

"This circuit is so special; you have the people everywhere who are so passionate about F1 - almost crazy in a good way - and the track is fantastic, you have such nice high speed corners one after the other.

"It's so enjoyable, you don't want to come into the pits, but want to stay out on track."