The newly-rescued Brawn GP on Thursday continued to astound its rivals at Barcelona, on the last day of the final group test of the winter.

The newly-rescued Brawn GP on Thursday continued to astound its rivals at Barcelona, on the last day of the final group test of the winter.

Not only was Rubens Barrichello atop the timesheets, he bettered teammate Jenson Button's astonishing time on Wednesday and was nearly a full second clear of the quickest of his dumbfounded rivals.

The cynics are not now wondering if the BGP001 is fuelled light, but how much below the mandatory 605kg minimum weight it is circulating.

Up and down the pitlane, however, the message is clear: if Brawn is running representative fuel and a legal weight, the car is the runaway favourite to win in Australia.

Asked by La Gazzetta dello Sport who he would put his money on for Melbourne, BMW's Robert Kubica laughed: "Button!"

"Seeing a truly competitive car again really excites me," said Barrichello, who switched from Ferrari to Brawn's previous guise Honda in 2006.

"I feel bursting with energy. After two or three not so good seasons I'm feeling positive again. And I'm back to win," the Brazilian added.

Felipe Massa, Barrichello's younger countryman, agrees that on current form, Ferrari is no longer leading the field.

"We are still very competitive but behind the Brawn," he acknowledged. "I would say their lap times are just much quicker than anyone can do.

"I'm not an engineer so I cannot say they have ballast or not, but even if they have no ballast and they put ballast (in) they will be quick anyway.

"It is very surprising," added Massa, the 2008 championship runner-up.

Button, to occupy the sister Mercedes-powered Brawn in 2009, beamed as he told reporters the real test will be at Albert Park in two weeks.

"This is fun but we have a long way to go and we still don't know where we stand," the Briton insisted. "It's a quick car and there is also room for improvement."

Quoted by Italy's La Gazzetta dello Sport, the 29-year-old added: "For sure we will be fast at the first race but I don't know about after four or five races."

Button said the F1 fraternity should not be surprised about Brawn's form.

"I like surprising people, but I really want to surprise people at the races.

"Perhaps people forgot that we have good facilities and talented people who can make competitive cars. Before we went on the track many people in the factory knew we had done a good job.

"When I went to the factory after the (Honda withdrawal) announcement I found everyone at work as usual. The results show that we kept our heads down on our goals.

"We seem quick at the moment but we don't know about the others: Trulli looks excellent, and Ferrari. There are many people who with little fuel can do very quick lap times," said Button.

The 2009 pre-season has now concluded for many teams, with the exception of Brawn, Renault, McLaren and Williams, whose last winter outing will be at Jerez next week.

Force India, meanwhile, will shake down a second car at Silverstone on Tuesday, with test driver Tonio Liuzzi at the wheel.


Gallery: Brawn GP Sets Another Lap Record - this time by Barrichello