Sebastian Vettel targets fourth title

Formula 1 champion Sebastian Vettel has revealed that he has lost none of his motivation despite securing the World Championship crown for the past three years.

The 25-year-old overcame a spin and a crash to finish sixth in last month's Brazilian Grand Prix, a result that secured the title for the German.

"As a team member I want us to be as successful in 2013 as we have been this year and the two previous years. And personally, I never had to simulate motivation - that is part of my nature," he told the official Formula 1 website.

Vettel is one of just three drivers - the other two being Juan Manuel Fangio and Michael Schumacher - to secure the crown three years in a row.