|Australian Grand Prix|
|Date: Sunday, 20 March Circuit: Albert Park Start time: 05:00 GMT|
|Coverage: Live on BBC Radio 5 live, BBC Sport website and BBC Sport app, plus live text commentary.|
|First practice on Friday 01:30 GMT (BBC Radio 5 live sports extra and text commentary from 01:00)|
Lewis Hamilton believes Ferrari will provide a tougher challenge to Mercedes than expected at the season-opening Australian Grand Prix.
Ferrari driver Sebastian Vettel said reigning champions Mercedes started the weekend at Melbourne's Albert Park as "favourites".
But Hamilton believes Ferrari were deliberately talking their chances down before Sunday's race.
"I think Ferrari have something up their sleeve," he said.
"I think they are going to be a lot closer than they talk about. I think they are going to surprise. They are arriving on a low but will deliver high."
Ferrari set the pace on five of the eight days of pre-season testing in Spain in the run-up to this race but Vettel said he believed they were still not yet at the level of Mercedes.
Asked if Ferrari had enough performance to trouble Mercedes, Vettel said: "I think we have. The question is: 'Are we ready in time?'
"I think we did a good step over the winter. Mercedes are the favourites but the target is to turn things around and be the favourite in the future."
He added: "We know we are still a little bit behind. We will try to be closer this year. How close I don't know yet, but we have a plan. Bit by bit, I hope we improve."
Hamilton has won the last two world titles to add to the first he won with McLaren in 2008 and has achieved his aim of matching the achievements of his childhood idol Ayrton Senna - both in championships and races won.
But Hamilton said he was as motivated as ever to keep on winning.
"You are always searching for perfection, always learning, always growing, inside and outside," he said. "I'm just looking forward to that journey.
"You're always looking for that perfect lap, that perfect race and raise the bar every time you go out, because it can always be raised."
The season starts with a raft of rule changes, including a new qualifying format and stringent restrictions on the amount of information teams can pass to drivers over the radio while they are out on the track.
Hamilton said he was not concerned about the effects of either change but team-mate Nico Rosberg believes the radio ban could have "a big influence."
The German added: "It's great because we're not muppets any more. It is now down to us to get the job done. It is going to make it more challenging as a result."