Sir Stirling Moss has suggested that, should Mark Webber win this year's F1 world championship title, it would be down to Sebastian Vettel - and not just if the German cedes victory to deny Fernando Alonso the crown.

Speaking to Melbourne's Age newspaper, the motorsport legend claimed that, despite Webber surprising Vettel with pace and consistency that no-one expected from him ahead of the 2010 campaign, it is the German's potential that is forcing his team-mate to find new reserves of performance.

''I think Vettel is probably making him find out where his limits are, I really do,'' Moss said, pointing to Webber's hitherto softer team-mate match-ups, "'I would say that Vettel is as fast as any driver out there now, and the fact that Vettel is a team-mate makes it even more important for [Webber] to have a go."

Webber is the leading challenger to Ferrari's Alonso heading into this weekend's final round in Abu Dhabi, but needs the Spaniard to finish third or lower if he is to have a chance of the title. Even then, finishing second behind team-mate Vettel is not an option and, given the German's pace in recent races, he may need him to move over as RBR attempts to stymie Alonso. Should the Spaniard not finish, however, second place behind Vettel would not be enough to deny the German the title on the basis of who has more wins on the season.

While his comments may appear to be disparaging towards Webber, meanwhile, Moss insists the opposite is true, praising the Australian for the way he has risen to the challenge of guiding Red Bull Racing towards what could be its maiden F1 drivers' title.

"He's rallied around to it amazingly," the 81-year old stressed, ''He's doing a great job there. He's fit and he's really consistent now. I'm very much impressed by how much he's improved.

"Mark's as fit as anybody I reckon who is ten years younger," he continued, reflecting on rumours that Webber may call time on his career in a year or so, despite being just 34, "[Juan Manuel] Fangio was 47 and races in those days were three hours long. Of course, the races today you have a lot more G-force and whatever but, if Mark wins [the title], I shall be very surprised if he doesn't go on."