Button upbeat on Brawn GP's form

The team formerly known as Honda was saved by an 11th hour buyout after months of doubts about its future.

Despite that, and despite joining testing late, the team has been impressive and some rivals believe it is the favourite squad to win in Melbourne.

Button admitted on Thursday that the team's situation should mean they are underdogs, but the Briton acknowledges the BGP 001's testing form has upped the expectations.

"We should be the underdogs, being a private team with a customer engine, but looking at the testing times we're not," he said. "I don't know if we are the favourites or what but it's nice knowing we have a competitive car.

"We don't know how competitive it is, but for me, all I know is that it's a great car to drive and I feel that I can really work with it and the changes that I make can make a difference."

Button, whose future in F1 was in doubt due to the problems with the team, conceded the winter had been hard, especially following a frustrating 2008 season.

But the one-time GP winner is adamant the team's decision to switch its focus to 2009 early is now paying off.

"It's difficult coming from what we had to having a competitive car, but we always knew that halfway through the season we'd stop development because we had to focus everything on 2009 and I think it was the right thing to do," Button told reporters.

"At the time it didn't feel right because the car was bad and we wanted to improve it. From the drivers' point of view driving a car that is tough to drive is so frustrating, and then getting to November and hearing that Honda doesn't exist anymore - having those two bad years and not having the car to improve it was so frustrating.

"And to get a drive from that would have been very difficult so I persevered and gave my bit and worked as hard as I could to make sure the team existed."

He added: "It's obviously been a bad and good winter, but I'm very happy and I'm in a reasonable position now. We still don't know where we stand... but all I know is that we've got a good car and it feels good.

"It's a nice car to drive, really good to drive and I feel that I can really push it to the limit so as far as the feeling goes, it's good."

Button says the BGP 001 is a car he and the team deserve after all their hard work over the past seasons.

"It feels good and it's amazing what, after three days of driving an F1 car in winter testing people immediately, think 'wow, look at that. Where's that come from?' It's always been there but I've just not had anything near the equipment that I deserve and the whole team deserves," he added.

"We have a car now that is competitive and I've just got to make sure that it stays competitive and we can keep improving it through the year. That is always the key to fighting for a world championship, not that we ever have.

"But I've been involved in Formula 1 for nine years, this is my 10th year, and it is the key to be commitment through the year but also to keep improving the car all the way through the season."