Vettel faces uncertain future

Season-opening Melbourne GP will set the tone for an exciting year

The prospect of seeing Sebastian Vettel beaten for the first time since last July is just one of the many novelties Sunday's season-opening Australian Formula One Grand Prix promises to deliver.

Just how much trouble Vettel's Red Bull team might be in is one of the questions waiting for an answer as the sport's unpredictable new turbo era whooshes into action at Melbourne's Albert Park circuit.

The quadruple world champion won the last nine races of 2013 but the 26-year-old German spent much of his time during the pre-season tests in Spain and Bahrain watching the car being worked on in the garage.

Red Bull are braced for a reality check as they and partners Renault work against the clock to fix the troublesome 1.6 litre V6 hybrid turbo engine and its complicated new energy recovery systems.

Rivals Mercedes, under new leadership following the departure of Ross Brawn, have been racking up the laps with far less hassle.

"Mercedes have got a bit of a march on people. They invested more, they invested earlier. They've got themselves into a good position," Red Bull team principal Christian Horner told reporters.

"If Mercedes were to finish two laps ahead of the opposition in Melbourne, that wouldn't be a surprise, based on what we've seen in pre-season testing. It's massive,” said Horner.

Horner's words may be a part of the pre-season mind games, repositioning Red Bull as underdogs but Mercedes drivers Lewis Hamilton and Nico Rosberg have sounded quietly confident about a car that is sleeker than many of its 'ugly' new-look rivals.

"With all the changes within the sport and the hard work that's been going on within the team, I believe this can be our year to really show what we're capable of," said Hamilton.

Ferrari will be hoping to challenge with their new lineup of champions following the return of Finland's 2007 title winner Kimi Raikkonen - triumphant in Melbourne for Lotus last year - to partner Fernando Alonso.

The cars will sound different without the old V8 engines and will also be far less reliable at first, with any repairs likely to take far longer due to the complexity of the power units.

How many cars will start from the grid, let alone finish the race now that fuel economy is a big factor, is another uncertainty.