SHANGHAI (AFP) - World champion Michael Schumacher said here he will keep racing as long as he remains at the top of his game.
"Nobody knows how long I can do it," said the Ferrari star who wrapped up his seventh drivers title at the Belgian Grand Prix.
"At this level when somebody beats you ... when you're not competitive any more then it's time to stop," added the 35-year-old who has dominated this season, winning 13 of the 15 races so far.
While his performance has been awesome, his domination has sparked serious soul-searching among organisers seeking to halt plummeting television ratings.
China's inaugural Grand Prix on Sunday is seen as an opportunity to win a new generation of viewers and provide a financial shot in the arm for sponsors and teams.
Schumacher said he was not surprised by his popularity in China despite the country having no history of motor car racing.
"I knew China is very interested in our sport," he said. "It's great to come here and know people love our sport."
His teammate Rubens Barichello, who sits 27 points ahead of third-placed Jenson Button of BAR-Honda, said he was gunning for a win Sunday to back up his victory a fortnight ago in Monza.
"Second place is better than third, but I'll be fighting for a win," said the Brazilian.