Bernie Ecclestone has revealed that a fourth straight F1 world championship success for Sebastian Vettel would not necessarily be a bad thing for the sport, but admits that he has not yet identified a favourite for 2013.

With pre-season testing doing its usual job of revealing little in terms of a pecking order ahead of this weekend's Australian Grand Prix, Ecclestone concedes that he remains as uncertain as anyone when it comes to predicting the outcome of the championship, but insists that he would not complain if Vettel were to emerge on top once more.

"It wouldn't be bad - and it would just be as good if somebody else wins," the octogenarian told the official F1 website during his regular pre-season interview, "He can't stand losing. Sebastian is a very competitive person. Don't misjudge the way he is - it is not easy going by any means to have that sort of success. He works hard at winning. It doesn't come easy."

Ecclestone, who regularly plays backgammon with the three-time champion, is under no illusion that Red Bull will be one of the teams to beat in 2013, despite inconclusive testing performances, but expects the Milton Keynes outfit to be challenged by more than just McLaren and Ferrari this season.

"I very recently spoke to Stefano [Domenicali] and he said that he still expects Red Bull to be the danger for them," he said of the Scuderia, "And I agree: they are - and they are super competitive. And, from Red Bull's point of view, their biggest competitor will be Ferrari.

"[But], in the tests, [Mercedes] have shown that they are much more competitive than in previous times. When I spoke with them about taking Lewis [Hamilton], I said 'if you take him, you get the right sort of people because they think they are joining a winning team now'. Niki [Lauda] and Toto [Wolff], that looks good, so I am sure that they will be competitive. I would be hugely surprised if they don't win races - on merit and not for other reasons!"

With Hamilton leaving McLaren for Mercedes, the pressure will be on Sergio Perez to fill the void, and Ecclestone doesn't share the pessimism of some when it comes to rating the Mexican.

"Maybe we will see that their 'second driver' will not really be second driver - that he is as good as everybody believes," he suggested, "I think it will be good for Jenson [Button] too, as he will now feel that he is in charge, whereas before he might have thought that he was 'number two'. Now he is 'number one' and we will very likely see a different Jenson. That might be good for him. Perhaps....."

With Mark Webber hoping to challenge Vettel from within the Red Bull camp, a resurgent Felipe Massa backing Fernando Alonso up at Ferrari, and both Kimi Raikkonen and Romain Grosjean suggesting that Lotus can be a more regular racewinner, Ecclestone admits that he is excited about the year ahead - even if he has no idea where to put his money.

"Oh yes!" he said when asked whether he still anticipates the start of a new season, "[But] I haven't got the slightest idea - like everybody else - who is going to make it and who is not. Isn't that what makes the suspense?"