Formula One starts the season with fresh faces and a record 21 races including the first in Azerbaijan, even if Lewis Hamilton becomes a four-times world champion with Mercedes. Speaking during a Mercedes event in Fellbach near Stuttgart on 11 March, Hamilton said he was "excited to go back to competition. Testing is not competition."

"I'm very, very excited, looking forward to getting back in and the challenges I'm going to face this year are all unknown, even though I've been doing it for a long, long time," Hamilton said.

During testing some teams evaluated a "halo" safety device which is being proposed for the 2017 season. The one that Ferrari evaluated looks like a hoop at helmet level supported on a strut in front of the driver's face. But Hamilton has spoken out against it, saying it looks ugly and he would not use it. The safety hoop is designed to stop debris, or even cars, hitting the driver's head in a race or during an accident.

Felipe Massa received a fractured skull through being hit by debris in 2009, Formula Two driver Henry Surtees, son of former F1 world champion John Surtees, lost his life in the same year when hit by a bouncing tyre during an accident, and Indycar driver Justin Wilson was killed by a piece of debris last year. John Surtees has requested Hamilton to think again about the "halo," saying he believes his son might have been saved by such a device. Hamilton said he respected Surtees' opinion, and his motives.

"I'm entitled to my own opinion. Doesn't mean I'm right, doesn't mean he's right, doesn't mean anyone is right," the world champion said. "We all have a right to our own opinion, and I don't shout anyone down for their opinion."

Rosberg, runner-up for the past two seasons but winner of the last three races of 2015 from pole position, has a point to prove and could be on the cusp of something remarkable if he can pick up where he left off in Abu Dhabi last November.

"I can't predict the future, I know that it is going to be difficult, said Rosberg. "Lewis has beaten me in the last couple of years. So it'll be a tough challenge. But it will be a great battle. I love to fight...and to try to win. Of course, that's going to be awesome and that's why I look forward to the season."

Vettel, who won four titles in a row with Red Bull before Hamilton dethroned him in 2014, will want to deny the Briton the satisfaction of equalling his tally and becoming only the fifth quadruple champion. Both Germans have pounded out the laps in pre-season testing in Barcelona, with Mercedes the most reliable car and Ferrari setting the more eye-catching times.