It’s another year in the circus that is Formula 1 as the teams, drivers and fans get into gear for the first race of the season tomorrow in Melbourne.

2012 proved to be another coronation for Red Bull’s Sebastian Vettel as the 25-year-old German became the youngest triple-World Champion in the history of the sport.

But he will face a tough battle to keep hold of his crown this season…

Ferrari

Fernando Alonso, handicapped by an uncompetitive Ferrari, was only narrowly beaten to the world title last year. But the signs from pre-season testing suggest that the Prancing Horse will not be off the pace to the same extent. The Spaniard is arguably the most complete driver on the grid so he will be a major threat to Sebastian Vettel, especially as his team-mate Felipe Massa appears to be rediscovering his mojo.

Red Bull

Red Bull did not play their full hand in January or February – but they never really do in pre-season. Running relatively high on fuel, their true pace was masked somewhat. But with multi-championship winning designer Adrian Newey on board, Red Bull – and Vettel in particular - will still be the team to beat.

The importance of a strong qualifying performance will be the key for Red Bull as Vettel’s stellar success has been built on getting onto the front row of the grid and building up sizeable advantages in the early laps of races.

McLaren

McLaren are entering interesting territory as they adjust to the post-Lewis Hamilton reality. Jenson Button’s step up to No 1 within the team was a natural progression.

They seem to be struggling for raw pace ahead of the Australian Grand Prix but there are question marks over reliability – an issue which has dogged them in recent seasons and partially contributed to Hamilton’s departure.

There is also the factor of setup. It has been well documented that Button struggles when the car is not setup exactly to his specifications, while Sergio Perez is an inexperienced No 2. But the issue of setup may have been solved already after Hamilton’s departure as the team will now be built around Button. But it may turn out to be a season of transition for McLaren.

Mercedes

The German manufacturers will be dark horses for both the driver and constructor crown. 2013 was expected to be a year of transition for Mercedes after an underwhelming three years and before Formula 1 makes the switch from V10 to V8 engines.

But going by their performances in testing, Lewis Hamilton and Nico Rosberg have the pace to put themselves in contention for podiums and race wins. Hamilton is secondly only to former team-mate Alonso when it comes to drawing performances from sub-par cars, so if the Mercedes is underwhelming, he could still be a threat. But first of all, Hamilton will hope win the internal team battle and get one over on his friend and team-mate, Rosberg.

Lotus

Lotus exceeded expectations in 2012 as the returning Kimi Raikkonen picked up a race win in Abu Dhabi and ultimately finished an impressive third in the Driver’s Championship.

The question is whether they can make a step forward and have Raikkonen challenging for race wins more consistently. As the Finn so eloquently informed his mechanics over the team radio last year in Abu Dhabi: “Leave me alone, I know what I’m doing”. Raikkonen is one of the quickest drivers on the grid, so it will be up to the team to deliver the goods.

The other issue is his team-mate Romain Grosjean. Qualifying and race pace was not the problem for the Swiss-born Frenchman. It was his regular crashes with other drivers that generated much controversy and almost threatened his place in the sport ahead of 2013. Lotus’ hierarchy will hope that he has ironed out this potentially dangerous flaw after finishing a solid eighth in the championship.

The Best of the Rest

After huge success in the 80s and 90s Williams have been in the doldrums for the past decade but 2012 was encouraging as Venezuelan driver Pastor Maldonado claimed the team’s first race win since 2004 at the Spanish Grand Prix. Williams will not be challenging for race wins, but will be aiming for regular points finishes. Maldonado has a new team-mate in long-time test driver Valterri Bottas of Finland.

They will be involved in the midfield battle with Sauber, Toro Rosso and Force India. Sauber have completely revamped their driver lineup, bringing in Nico Hulkenburg and Mexican rookie Esteban Gutierrez, while Adrian Sutil has returned from a suspended prison sentence to partner Scotland’s Paul Di Resta at Force India.

For the past few years, the backmarkers have consisted of Marussia, Caterham and HRT. But with Hispania Racing Team withdrawing from the sport, the question which one of the other two teams can finally make begin to mix it with the midfield pack.