Lewis Hamilton believes his time is running out, as he seeks to add to his only drivers' championship from 2008.
Hamilton decided to swap McLaren for Mercedes-Benz in 2013, with a long-term view of challenging for the championship. His motivation for a move to Mercedes was thought to be based on the introduction of the new 1.6 litre V6 engines for 2014, along with his crumbling relationship with the McLaren hierarchy.
The 28-year-old has now spoken of his disappointment at holding just one title and wants to be remembered as a great: “Time is slipping away,” Lewis told The Sunday Times' Driving Magazine.
"It's been five years since I won the World Championship. When I was in the lower categories I would win a championship every year or every other year.
"There are a lot of drivers that haven't won a World Championship, so I feel at least grateful that I have one, although one is less prestigious now because so many people have won a championship. Now the people who have two or three or four: [that's what] makes you special.
"I'm getting older and I don't have forever in this sport. So I definitely start to think what I want people to remember me as: I just want to be known as a hard, out and out racer."
Hamilton also says that he feels he has not had the car to challenge for a title since his dramatic, last-gasp success in 2008: "I got to F1 and nearly won in my first year, then won I won in my second year," Hamilton added.
"I've never had a car to really compete since then. The car makes such a big difference so you're just wasting away your best years."