FERRARI
Drivers: 5-Sebastian Vettel (Germany), 7-Kimi Raikkonen (Finland)
Specs: SF71H car. Ferrari engine
Vettel (30) was runner-up last year with five wins to Hamilton's nine. This year is the 10th since Ferrari last won a title and the team hope to end that, with the focus on Vettel. Raikkonen (38) last won a race with Lotus in 2013 and is the oldest driver on the grid. He looks like being in his final season and will be expected to play a supporting role.
Likely outcome: Top three, but maybe only third.
Photo by Albert Gea/Reuters

FORCE INDIA
Drivers: 11-Sergio Perez (Mexico), 31-Esteban Ocon (France)
Specs: VJM11. Mercedes engine
Punching above their weight for the past two years, Force India face a big task to finish fourth for the third year in a row. Perez (28) and Ocon (21) are likely to be in the sights of Renault and McLaren, if not Williams. Testing was unremarkable but a new package is promised for Melbourne.
Likely outcome: Dropping down. Fifth at best.
Photo by Patrik Lundin/Getty Images

HAAS
Drivers: 8-Romain Grosjean (France), 20-Kevin Magnussen (Denmark)
Specs: VF-18 car. Ferrari engine
The Ferrari engine is strong and Grosjean (31) and Magnussen (25) are experienced. How good the car really is remains to be seen but it has made people take notice with good reliability and pace in testing.
Likely outcome: Moving up. Sixth should be a target.
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MERCEDES
Drivers: 44-Lewis Hamilton (Britain), 77-Valtteri Bottas (Finland)
Specs: WO9 car. Mercedes V-6 engine
Hamilton (33) is going for his fifth title and starts as a favourite with the new W09 car looking quick and very reliable. The Briton was fastest in the first pre-season test but the top teams could be closer this year. Bottas (28) needs to convince Mercedes to keep him on with others eyeing his seat.
Likely outcome: Champions for fifth year in a row. Hamilton to defend his title.
Photo by Mark Thompson/Getty Images

MCLAREN
Drivers: 14-Fernando Alonso (Spain), 2-Stoffel Vandoorne (Belgium)
Specs: MCL 33 car. Renault engine
Having ditched Honda, McLaren see this season as the start of the comeback. Reliability problems in testing have raised concern, however. Alonso (36) has a full world endurance season to do as well, but can be counted on to give everything as ever. Vandoorne (25) needs to make more of an impact.
Likely outcome: Moving back up the grid. The top four is the target but probably not yet.
Photo by Mark Thompson/Getty Images

RED BULL
Drivers: 3-Daniel Ricciardo (Australia), 33-Max Verstappen (Netherlands)
Specs: RB14 car. Renault engines re-branded Tag Heuer
Verstappen (20) ended 2017 strongly, his two wins in the last six races matched only by Hamilton. Ricciardo (28) is out of contract at the end of the year but the team want him to stay. Much will depend on the Renault engine but Red Bull should be closer to the top and aiming for wins.
Likely outcome: Top three, more likely second than first.
Photo by Mark Thompson/Getty Images

RENAULT
Drivers: 27-Nico Hulkenberg (Germany), 55-Carlos Sainz (Spain)
Specs: RS18 car. Renault engines
The former champions are on the way up, with hungry drivers and an engine that took Red Bull to three wins last year. Hulkenberg (30) could stand on the podium for the first time. Sainz (23) has settled in since joining last year and will push him hard. Mercedes boss Toto Wolff reckons Renault could turn out to be the most improved team of the year.
Likely outcome: The best of the rest in fourth.
Photo by Patrik Lundin/Getty Images

SAUBER
Drivers: 9-Marcus Ericsson (Sweden), 16-Charles Leclerc (Monaco)
Specs: C37 car. Ferrari engines
Alfa Romeo backing and the latest specification engine from Ferrari, after using an old model last year, will help but the car has looked tricky in testing. Leclerc (20) is last year's F2 champion and seen as a future Ferrari driver. He could well beat Ericsson (27), who has not scored a point for two years.
Likely outcome: Another year as back-markers but closer.
Photo by Mark Thompson/Getty Images

TORO ROSSO
Drivers: 10-Pierre Gasly (France), 28-Brendon Hartley (New Zealand)
Specs: STR13 car. Honda engines
The Honda engine that plagued McLaren and led to the end of that partnership has been reliable in testing. That will be key to the season, with the team now the full focus of a manufacturer for the first time. The drivers' lack of experience could be telling, with Gasly (22) and Hartley (28) starting their first full seasons.
Likely outcome: Sixth, equalling their best ever, if Honda have really got their act together.
Photo by Patrik Lundin/Getty Images

WILLIAMS
Drivers: 18-Lance Stroll (Canada), 35-Sergey Sirotkin (Russia)
Specs: FW41 car. Mercedes engines
The youngest line-up on the starting grid, with rookie Sirotkin (22) on one side of the garage and Stroll (19) on the other. The lack of experience could count against them, and the Mercedes-powered car has not impressed in testing.
Likely outcome: Only one direction and that's downwards, possibly as low as seventh.
Photo by Patrik Lundin/Getty Images