Michael Schumacher is back, fired up and ready to take on three other champions on a starting grid that also boasts Ayrton Senna's nephew and a reborn Lotus team.

The new Formula One season that kicks off at Bahrain's Sakhir circuit next week has all the makings of a classic contest.

There are more rivalries and subplots than a mechanic could shake a spanner at, starting with Jenson Button and Lewis Hamilton at McLaren in a British team of champions against Schumacher's all-German Mercedes.

There are new teams, such as Malaysian-owned Lotus Racing whose name brings back memories of the great marque led by the late Colin Chapman, and a new scoring system handing the winner 25 points.

Adding to the retro feel is a ban on refuelling stops, taking the sport back to where it was nearly two decades ago when Schumacher had still to win the first of his seven titles.

In a mixture of new and old, a fistful of rookie drivers are joined by veteran Spaniard Pedro de la Rosa who might have thought his time was past.

Schumacher's return with the new Mercedes team, previously known as champions Brawn GP, at the comparatively old age of 41 and after three years in retirement, is the headline news.

The questions keep flowing. Is he still a winner? Can he beat the new crop of talent in a very different era to the one he dominated with Ferrari? Can he take that record eighth crown and add to his tally of 91 wins?

Over in the red corner, his previous nemesis Fernando Alonso will be out to stop him with the Italian team that the German once considered his own.

With Renault, the Spaniard won the last two championships Schumacher competed in and he now intends to chalk up a third title with Ferrari.

Brazilian Felipe Massa, Schumacher's best friend on the racetrack and now Alonso's team mate in an all-Latin line-up, will try to beat both men on his return from the life-threatening head injuries he suffered last July.

Ferrari have already looked the team to beat from pre-season testing, with Red Bull and McLaren close behind and followed by Mercedes.

"In terms of the drivers, you've got Felipe, Fernando, Jenson, probably (Red Bull's Sebastian) Vettel and Mark Webber because obviously they've got a quick car, Michael and Nico (Rosberg)," Hamilton said.

"It's really difficult to say who is the most competitive out of all of them, but at the moment the Ferrari looks the fastest I think," he added.

Rosberg has jumped ship from Williams to Mercedes, partnering Schumacher, while Poland's Robert Kubica arrives at Renault where he will be partnered by Russia's first driver Vitaly Petrov.

Brazilian Rubens Barrichello, Button's Brawn team-mate last year, is starting over at Williams along with German rookie Nico Hulkenberg.

Toyota and BMW have departed, although the latter's name lives on for the time being at Sauber, while the grid has expanded from 10 to 12 teams with the arrival of Virgin Racing, Lotus and Spanish-based HRT.

Virgin, owned by Richard Branson, will be taking on the Lotus team of Airasia owner Tony Fernandes in a battle of aviation entrepreneurs.

Bruno Senna, nephew of the late triple champion, has signed up for the HRT team with Indian Karun Chandhok.

The calendar has been expanded to 19 races from 17, with Canada returning and South Korea making its debut.

"This year I would say it's been fantastic, because of the publicity we've had, with world champions in competitive cars, new teams coming in," said Button.

"I can't wait for the first race. I think it's going to be a very special season," he added.