Mark Webber: 'My F1 motivation has waned over the years'

Red Bull driver Mark Webber has revealed that he has struggled to be motivated for the Formula 1 season over the last few years.

The 37-year-old will leave the sport at the end of the season to compete for Porsche in the classic Le Mans 24 Hours race.

While the Australian has admitted that he is perhaps leaving F1 a season too early, he does believe that he is making the right decision.

"I've been on the edge with F1, motivation-wise, for the past couple of years," Webber told F1 Racing magazine.

"You have to be driven. You turn yourself around each winter and the fire in the belly is not quite what it was when you were 24."

Webber, who has won nine Grand Prix, has spent 12 years in F1.