Stoner says 2008 starts this weekend

The new world champion has been enjoying racing with the pressure off since he sealed the title in Japan, but he feels that it is time to start working as hard as possible ahead of his title defence next season.

"After this race we start testing for next year, and I believe that this is where our season starts for next year," the Australian said ahead of this weekend's finale at Valencia.

"We've won the championship, and I'm having a lot of fun racing at the moment, but it's time to get our heads down again.

"We've got two tests at the end of the year, and we're looking forward to them. We need to come up with a package that will hopefully be better for next season."

The 22-year-old would not be drawn into making any predictions for next year, but he did say that after winning the title this season, any success in the future would just be a bonus.

"People can make assumptions all they want, but until we get down to racing no one can be sure what's going to happen," he said.

"I'm just happy to be world champion, even if it's just once. We've accomplished a huge goal in my life, and anything from now is a huge bonus."

Stoner will be chasing his 11th victory in 18 races this season when he starts at the Spanish track on Sunday.