Sebastian Vettel has admitted that there is no guarantee of success in the coming seasons despite his all-conquering display this year.

Vettel clinched his fourth consecutive Drivers' Championship earlier this season and set a new record for consecutive wins in one campaign with his eighth in a row at the United States Grand Prix on Sunday.

The German could equal Alberto Ascari's all-time record of nine wins in a row, set in 1952-53, with victory in the final race of the season in Brazil next Sunday, but the Red Bull driver has stressed that such success should not be taken for granted.

"It's a little bit of a shame that because of the run we've had lately people take it as guaranteed you deliver the result on a Saturday and Sunday. People tend to respect the result, what it means, the effort behind it, but as an athlete you have ups and downs," PA quotes Vettel as saying.

"Right now you could say it's rather more up than down, but you never know what's going to happen. Next year is an unknown. I'm sure we will push very, very hard and I'm sure we will fight a lot to maintain our position, but there's no guarantee next year will be like this year. With the new regulations coming in, nobody really knows where they will stand.

"You will have the big teams in front, but the question is: who? And what about the gaps? In qualifying there was a tenth [of a second] between Mark (Webber) and myself, which is very, very small. There's a reason to believe next year the gaps will be bigger and the season will be less consistent for everyone. It's unknown at this stage. That is why we need to enjoy the moment and the days we're having."

Success in Brazil next Sunday would also see Vettel equal Michael Schumacher's record of 13 wins in a single season.