BAR-Honda believe they will pose a threat to Ferrari, Williams and McLaren at the top of Formula One this year.
Button believes the new BAR will be competitive
The team launched their new car in Barcelona on Sunday, buoyed by the results of winter testing.
Lead driver Jenson Button said: "The car is a major step forward. I think the year will bring us podium finishes and, who knows, perhaps my first win.
"I feel very confident we are not overstating our aims when we can say we can fight with the top three."
Button believes BAR will be competitive from the start of the season.
"You're always going to need a little bit of luck on your
side to get that first podium," he said.
"But if we work like we have been working over the
winter... I think there's no reason why we can't be on the podium at the first race in Melbourne."
BAR have been testing a hybrid version of their new 006 car for several weeks and have been particularly enthused by their new Michelin tyres, having switched from Bridgestone.
Button added: "We have done a lot of testing with the interim concept car, around 4,000km this year so far, and I think we've used out time very well over the winter.
"We're still not completely sure about the new car but its
promising and the good thing is that it is very stable."
Technical director Geoff Willis said: "Testing with Michelin has given us the confidence that we have made good progress this winter."
Honda have produced a new engine for the new rules, which state that only engine can be used per car during a Grand Prix weekend.
The Japanese company say they have managed to maintain last year's power levels while finding the necessary improved reliability.
"We have extended our engine's life, while making it smaller and lighter with a lower centre of gravity," said Takeo Kiuchi, Honda's F1 project leader.
Button will be joined by Japanese driver Takuma Sato, who has replaced Jacques Villeneuve.
Sato said: "Jenson and I will be a strong partnership, the car looks very good and I think we have every reason to feel positive."