Sebastian Vettel is hopeful he will be stronger this season now he has won the world championship.

Vettel will be out to try and defend his crown in F1 2011 and while he has been pleased with the new RB7 in pre-season testing, he remains cautious about his prospects in the countdown to Melbourne's Australian Grand Prix.

"It's very difficult in the beginning to tell," he replied when asked about the pecking order. "I don't have an advantage with having the number '1' on the car.

"Obviously it's a nice feeling, and it was a great success and a big relief for me last year. Hopefully that has made me a bit stronger, but nevertheless, it will be a long, hard and tough season."

Pressed on if he feels different now he is world champion, Vettel added that for him little has changed.

"It was good to have a little bit of time for myself over the winter and to spend it with friends and family," he continued. "But now we've started again with the new car preparing for the new season, I wouldn't say life has changed too much.

"We seem to have a good car, but it's still too early to tell so we have to wait and see. There have been a lot of changes which has involved a lot of work over the winter trying to get the whole package ready to start the new season.

"Obviously it's very busy now with preparation work, and we're all doing our best to try to get the best possible package together. You can never have enough preparation to make the car ready.

"The tyres are very different to last year, but then again, it's the same for everybody.

"I think the racing will change and that one-stopping - maybe even two-stops - is impossible at this stage, so it will be at least three or four-stop races, which will make it interesting."