Lewis Hamilton has dismissed last year's double world championship winning Red Bull team as just a "drinks company" and is confident McLaren can win back the Formula One crown.

With his team promising some "dramatic changes" for Sunday's opening race in Australia, Hamilton expressed his determination that Red Bull – who would be favourites to sign the former world champion if he quit McLaren – would not continue to dominate the sport.

"I am 100 per cent certain that neither McLaren nor Ferrari will ever let that happen," he said. "They [Red Bull] have not been there as long as our teams. Our teams have got status they would like to keep.

"For many, many years it has been McLaren and Ferrari at the front and now we have got a new team that has come and knocked us off the top. But I am really certain that either team will do absolutely everything in their power to make sure they can remain at the top.

"Red Bull are not a manufacturer, they are a drinks company. It's a drinks company versus McLaren/Ferrari history. I don't know what their plan is. Our team is building to become a bigger manufacturer, like Ferrari, and I can only see our team being there for a ridiculous amount of time. It is a pure-bred racing team."

Despite his team principal, Martin Whitmarsh, promising upgrades he claims will be worth up to a second a lap, Hamilton is aware that McLaren will struggle to match the early-season pace of Red Bull, who are led by their brilliant designer, Adrian Newey.

"Red Bull will have improved their reliability from last year," he said. "They will have the pace and the reliability this year, as will Ferrari. Those two are definitely the hardest to beat.

"Sebastian's [Vettel] confidence, as champion, has probably gone up but I would say more so because for the second year in a row he has probably got the fastest car. He has got a ridiculously fast car but so has Fernando [Alonso], it seems.

"I am sure Mark [Webber] will be competitive as he was last year. I am sure he will want to bounce back from last year. He had a difficult year with lots of ups and downs and this year he will want to be strong and more consistent."

Hamilton, like his team-mate Jenson Button, has been frustrated by McLaren's poor downforce levels in pre-season testing. But he added: "As an athlete, as a competitor, optimism is something you have to hold. You always have to have that.

"I'm never one to give up. I'm not going to sit here and say 'the championship is over, blah, blah, blah'.

"I'm ready and when the car is ready I will be at the front and I will win races. Just because we don't have a winning car right now, that doesn't mean it won't become a world championship-winning car. We'll see."

Whitmarsh believes the changes to the car are a risk worth taking. "I'm not satisfied with where the car was on reliability or performance in the tests," he said. "We have made some fairly dramatic changes and those changes we'll see in Australia.

"There's some risk in that but I think it was the right thing to do and we're hoping that risk comes off and the car is a lot more competitive," he said. "I think it will still be a challenging weekend but I'm hopeful that we'll put on more than a second in performance."

Hamilton, who has a waspish sense of humour, might be tempted to wear the convict cuffs and leg fetters associated with Australia's earliest visitors from Britain when he appears in Melbourne.

Last year he had his road car impounded by police after performing burn-outs outside the paddock and he was charged with driving offences in what has become one of the most officious of countries.

The year before that, at the same venue, he was found guilty of deliberately misleading stewards in what became labelled "Liegate" and McLaren were handed a suspended three-match ban.

But it has not been all bad. On his Formula One debut here, in 2007, he drove to a thrilling third. And in 2008 he won the first race of the season, which helped propel him to the world title.

So it was somewhat surprising when he said: "I don't have any mixed emotions. I don't go back there having any regrets. I have had a couple of interesting experiences that will hopefully help me steer clear of any other incidents in the future.

"I go back with a plan not to be in the stewards' office and not to be met by any of the police.

"But I feel really positive. I love going there, it is a great trip. It is a fantastic place and when the weather is great the circuit is fantastic too.

"I've generally had good races. I won in 2008, 2007 was my first race, which was pretty awesome, and 2009 was still a good race. I came from really far back with a car that wasn't so good.

"Last year I did a lot of overtaking but just didn't get what I should have resultwise."