Lewis Hamilton says he feels fresh and fit as he begins the defence of his Formula One world title in Melbourne this weekend – but admits every new season is a step into the unknown.
The main question will be whether rival teams can mount a stronger challenge to Mercedes, who last season won 16 of the 19 races.
“At this point in the year you don’t really know what to feel as a driver,” Hamilton said.
“You’re impatient to get back to racing but, at the same time, you never know what a new season will bring. Testing gives you a basic idea of whether the car feels good or not but, beyond that, it’s anyone’s game to win.”
Winter testing of the F1 W06 hybrid indicated Mercedes will again be the dominant force.
But potential rivals Ferrari, who now have four-time world champion Sebastian Vettel alongside Kimi Raikkonen, Red Bull (Daniel Ricciardo and Daniil Kvyat) and Williams (Felipe Massa and Valtteri Bottas) have also been buoyed by test results.
It remains to be seen whether McLaren have recovered following reliability problems in testing and Fernando Alonso’s crash in Barcelona last month which keeps the two-time world champion out of Sunday’s race.
“I’m sure the competition will be close and we should get exciting racing with plenty of battling for position – which is great because that’s what I love doing and that’s what the fans love watching,” Hamilton said.
“There are many good drivers out there and all of them want to win. You just have to want it more than they do.
“I feel fresh, I feel fit, I feel relaxed, I feel positive … I feel ready. I think as a driver you get stronger with every season, so I plan to be better than last year.”
Rosberg, who finished second to Hamilton in the championship last season, says his aim is to push himself even harder – and reverse the position in the final standings.
“In the end, it comes down to who can put the best season together overall and I have to make sure it’s the other way around this time,” the 29-year-old German said.
“Having said that, my teammate is just one of many strong competitors who I have to beat if I want to be world champion, so I’m just focused on being the absolute best I can be.”
Home fans in Melbourne will be rooting for Australian Ricciardo, who won three grands prix for championship runners-up Red Bull last season.
“Testing has been relatively good for us,” he said. “We had a few reliability issues but we racked up a lot of miles and learned a lot. I still feel that we have a bit more to go. But there is no better place to do this than going racing. I’m ready to go.”
McLaren line up with Alonso replacement Kevin Magnussen alongside Jenson Button as they hope to improve performance in their new Honda-powered MP4-30.
Race director Eric Boullier said the team has been working hard to improve the car’s reliability and data from the final test in Barcelona was “very encouraging.”
“Despite our difficulties, our package shows a lot of promise,” he said.
Ferrari meanwhile are optimistic of an improved season with four-time champion Vettel partnering 2007 champion Raikkonen.
“The atmosphere is very positive,” Vettel said. “Obviously there’s been a lot of change over the winter, with everyone working very hard and we’ve definitely improved as a team.”
Of the other teams, Lotus, now powered by Mercedes, hope to recover after a disappointing season, while Toro Rosso have Max Verstappen and Carlos Sainz Junior making their Formula One racing debuts – at 17 and 20 respectively the youngest driver pairing in F1 history.
Sauber’s driver line-up for Melbourne was meanwhile in doubt after an Australian court ruled that the team’s 2014 reserve driver Giedo van der Garde has a valid contract to race for them this year. Sauber have appealed the ruling.
If Van de Garde races, Sauber will have to drop one of their all-new 2015 line-up of Brazil’s Felipe Nasr and Sweden’s Marcus Ericsson.