Sebastian Vettel has refused to give up on the possibility of winning a fifth successive Formula 1 title this season.

Red Bull's struggles during winter testing has led to questions over the team's chances ahead of the new campaign, but Vettel claims that it is important to look beyond this weekend's Australian Grand Prix.

"Our preparation hasn't been ideal, and we are not in the best position for this race, but in the championship there is a long way to go," the German told journalists in a press conference.

"Two years back, Fernando [Alonso] was on the grid 1.5 seconds to pole position and he was very close to beating us to the title in the final race. Anything can happen.

"It's not a secret that you need very, very strong reliability to be a title contender. I'm looking forward to Sunday to see where we are."

Vettel won a record 13 races on his way to the title last season.