Formula One teams hate uncertainty. Formula One fans love it. At this weekend's season-opening Australian Grand Prix, it'll be the fans that get what they want.

After four years of an increasingly stultifying dominance by Red Bull and Sebastian Vettel, the only thing most experts agree on when discussing Sunday's race at the Albert Park street circuit in Melbourne is that it won't be those same blue cars at the front this time.

Aside from the likelihood of a Red Bull struggle, the pecking order for the Australian Grand Prix is anyone's guess, with nobody quite sure how the teams will adapt to the switch to V6 turbo hybrid engines. The change of powertrain — engine, turbocharger and increasingly important battery-stored hybrid power — has been problematical for all teams in preseason testing, most notably the Renault-powered teams, and particularly Red Bull.

Throw into the equation the reduction in fuel loads from an average of 160 kilograms (353 pounds) of fuel per race to a maximum of 100 kilograms (220 pounds), add a dash of the usual first-race teething problems and driver rustiness, and then factor in forecasts of rain and Melbourne's typical sudden shifts in temperature, and it becomes apparent why some observers are predicting that Sunday's race will not even have ten finishers to fill the points positions.

Some have complained that F1's rapid-fire regulation changes are becoming increasingly contrived and gimmicky — the double-points for the season's last race has outraged the purists — but the sport's officials can hardly be blamed for trying to shake up the sport.

Vettel, Red Bull and the team's ace designer Adrian Newey are all capable of staging a recovery from the likely slow start and earn a fifth-straight title, but if so, it will definitely not be a cakewalk like last year.

Instead it's Mercedes being freely tipped as the team to beat in the early races of the season after impressing in preseason testing, and hopes are high that the German mark can finally win its first-ever constructors' championship.

Lewis Hamilton and Nico Rosberg have been installed as favorites in betting markets for this weekend's race, and Red Bull principal Christian Horner was already sounding defeated.

"If they 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," Horner said.

"They invested more, they invested earlier. They have got themselves into a good position."

Ferrari is always a center of attention in any race, but the scrutiny will be further heightened in Melbourne as it is the first race with Fernando Alonso and Kimi Raikkonen as teammates. Many seasoned observers have said the team is simply not big enough for the two of them, and Albert Park will be the first skirmish as each tries to establish himself as the top dog.

McLaren is targeting Melbourne as the start of a renaissance after a highly disappointing 2013 that cost team principal Martin Whitmarsh his job. His place will be filled at the management end by Ron Dennis, who returns to trackside after five years in the company's management in England, and at the racing end by Eric Boullier, who has decamped from Lotus.

The loss of Boullier and Raikkonen from Lotus reflect the financial struggles of the team after the failure of a proposed takeover, and coupled with the Renault engine's myriad problems in testing, it has made Raikkonen's victory here last year already seem like another age.

"To be blunt, we are starting further back than we would like to be," technical director Nick Chester said. "The first two races of this season will be very challenging for us, however it also depends on the solutions that Renault Sport F1 will be able to bring to the table too," said Chester.