Patrick Dempsey

The 'Grey's Anatomy' star has hinted that his passion for high-speed racing is the main reason he hasn't moved on from the medical drama, which he has starred in since 2005.

He said: "The more money you have, the faster you go.

"[Racing] is a different type of passion. I'm an actor, so that's my job. That's my trade. Racing is always a discovery...finding different ways to be turned on. Race is always changing, and that to me is very exciting. And that keeps me alive."

The 47-year-old actor, who stars in a new documentary series 'Racing LeMans', which chronicles his journey to compete in the iconic 24 Hours of Le Mans race in France, also admitted that he only looks at the show as his day job but denied being tired of playing Dr Derek Shepard, according to

He said: "I'm not necessarily bored with the show. I'm incredibly grateful to have a show that's been on for ten years. But I'm not the creator. I'm not the writer. It's a trade, quite honestly. And that's fine. And when you're on the show, coming up on 200 episodes, it's about surviving. There's not a lot of homework. You learn your lines and try to stay present and try not to get caught acting. I'm glad I have the gig, but it's not the same as being in a race car."