LONDON, England - The prospect of seeing Sebastian Vettel beaten for the first time since July 2013 is just one of the many novelties Sunday's (March 16) season-opening Australian Formula 1 GP 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. The four-times F1 champion won the last nine races of 2013 but spent much of his pre-season tests in Spain and Bahrain watching his car being worked on in the garage.Red Bull is braced for a reality check as it and partner Renault work against the clock to fix the troublesome 1.6 V6 hybrid turbo engine and its complicated new energy recovery systems.MERCEDES IN CHARGERival Mercedes, under new leadership since the departure of Ross Brawn, has been racking up laps with far less hassle.Red Bull team principal Christian Horner said: "Mercedes has got a bit of a march on people. It has invested more, invested earlier, got into a good position. If Mercedes cars 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."All the Mercedes-powered teams are in pretty decent shape and Red Bull is not. We're on the back foot with a lot of ground to catch up."Horner's words may be a part of the pre-season mind-games, re-positioning Red Bull as underdog, 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.Hamilton, 2008 F1 champion with McLaren, said: "With all the changes within the sport and the hard work that's been going on within the team this could be our year to really show what we're capable of; I feel I'm equipped with the tools I need to succeed. I can't wait to get started."His win in Hungary in July 2013 was the last by any driver other than Vettel.Ferrari will be hoping to challenge with its new line-up of champions given the return of 2007 title winner Kimi Raikkonen - triumphant in Melbourne for Lotus in 2013 - to partner Fernando Alonso. Their cars will sound different without the V8 engines and will be far less reliable at first.Worse, any repairs are likely to take far longer due to their complexity.How many cars will start from the grid, let alone finish the race now that fuel economy is a big factor, is another uncertainty. Some insiders have predicted that the race could see less than half the field reach the chequered flag.In 1996, when Melbourne first hosted a GP, only 11 cars made it to the finish in a race won by Britain's Damon Hill for Williams. That team had a nightmare 2013 and scored only five points to finish ninth in the Constructor's list. Its crew are optimistic for 2014 after switching from Renault to Mercedes power.Brazilian Felipe Massa, who has joined Williams from Ferrari, lapped faster than anybody in Bahrain testing and put in plenty of distance. Finnish team mate Valtteri Bottas told Reuters: "The new car is really well built, good quality... very reliable and not slow. It's going to be an exciting season."McLaren, starting its final season with Mercedes before switching to Honda, is also looking for a strong start after failing to step on to the podium at all through 2013 and ousting team principal Martin Whitmarsh. Jenson Button has an exciting new team mate in 21-year-old Danish rookie Kevin Magnussen."We're not the quickest," said 2009 champion Button, who has won in Australia three times in the last five years. "We're looking at Q3 (qualifying in the top 10) and then a very good points finish."If we can get to the end..."Stay with Wheels24 for the first race of the 2014 F1 season in Melbourne.