While he clearly has time on his side, Damon Hill does not believe that Sebastian Vettel will have the chances to get close to fellow countryman Michael Schumacher's record of seven F1 world titles.

Vettel became the youngest double champion in history when third place in Sunday's Japanese Grand Prix gave him the point - and more - that he needed to deny Jenson Button a shot at the crown, but Hill insists that today's F1 playing field is to level to allow him to keep repeating.

"Michael's record is very unlikely ever to be beaten," the 1996 world champion and former BRDC chairman told BBC Sport, "They changed the rules because he was winning too much, [and] it's much more competitive now than it ever was. Vettel has that to contend with."

While he does not deny that Vettel will be a contender for future titles, Hill points to the undoubted support that his former nemesis received that enabled him to claim five straight crowns with Ferrari to add to the two he claimed with Benetton in the 1990s.

"All things were working towards helping Michael come to that level of championships," he noted, "There was a lot of momentum there that created the circumstances, [but] there were objections to the level of winning he was doing, and they changed the sport."

Hill also claimed that the jury was still out on exactly how good Vettel could be, having cruised to his second title in a superior car while potential rivals from McLaren, Ferrari and even with the Red Bull team squabbled over second place.

"[It's clear Vettel is] exceptional," the Briton admitted, "One thing that proves that is for a person of his age to cope with all the things that F1 can throw at you, apparently with very little difficulty. From the moment he put his Toro Rosso on pole and won at Monza [in 2008], that was a sign, a Schumacher moment. [Now], given the best car on the grid, he not only has grabbed [his opportunity] with both hands and made it work, but he's gone to another level. He's done some remarkable things with the best car, and his ability to pop a lap in right at the last minute of qualifying and just turn it on when he needs to shows he's got a bit in hand."

However, despite beating Fernando Alonso's record as the youngest driver to win two titles by almost exactly a year, and coming from behind to take the 2010 crown, Hill still reckons that the German can only be judged when he has to go head-to-head with one or more rivals for the crown.

"He's already got two in the bag, and another four titles in the next ten seasons wouldn't be out of the question, but it's never as straightforward as that," the former Brabham, Williams, Jordan and Arrows driver claimed, "You'd perhaps like to see him put through a bit of a tougher test of his mettle - a bit of pressure from another team, a contender. He has cracked under pressure this season - when Jenson was closing in Montreal, he dropped the ball.

"[Vettel]'s definitely top drawer but, in F1, you need some sort of personal rivalry to find out what is going on within each competitor. It seems to be that, any time there is another driver and the question is which is better, that spurs them on to push themselves to greater heights. It'll come because he's so young. He's obviously going to be driving for a few years yet and there are going to be much tougher times ahead."

Hill suggested that Alonso and Lewis Hamilton were the most likely drivers to push Vettel to new heights, and also found time to praise Jenson Button, but suggested that the German's current team-mate, Mark Webber, was not the man to challenge.

"I think Webber has done an amazing job and I think he's an incredibly good driver, but you have to face the fact that Vettel has got the edge on him, so he's not putting the pressure on Vettel that he needs for us to find out exactly what he's made of," he reasoned.

"I wouldn't like to guess what would happen if you put him up against a Hamilton. It might fire Hamilton up, [and] he might need to get some sort of rivalry going. Button has shown he's better than we ever thought he was, [while] Alonso is the sort of fiery character who you can imagine [making] it interesting them coming together."