Sebastian Vettel contemplates the future: "I may stop in five years"

Three times world champion Sebastian Vettel has said in an interview with the German Welt am Sonntag newspaper, one of the more serious papers in Germany, that he may quit F1 in five years time.

The 25 year old has won the world championship for the past three seasons and enjoys a strong lead in this year's points table after six of 19 rounds.

There has always been speculation that he might leave Red Bull and join Ferrari, part of a destabilising process which is common in F1 when a team and driver combination is winning.

But he has always denied rumours that he has signed any kind of pre-contract.

However he has not previously mentioned the possibility that his career may not run into his 30s. Because Vettel started at 19 and had won three championships by the age of 25 - an unprecedented feat - the risk of burn-out or drop in motivation is always there.

Maybe I won't be driving in five years because I'm tired of it," he said in Welt am Sonntag. "Maybe in five years I'll be with another team because I feel like a different challenge.

"Everyone evolves over the years and priorities shift."

Vettel adds that he is happy at Red Bull and that he can "not imagine sometime somewhere else to go."

On the face of it this is a non-commital answer and merely reflects reality, that one doesn't know what lies ahead in the future. It doesn't mean that he will cut short his career or move to another team.

But it does show that he's thinking about it. Both statements reflect his understanding that to maintain motivation as a top sportsman, you need to find fresh challenges.