Lewis Hamilton is looking forward to a battle with Sebastian Vettel this year, but believes he could only truly judge himself against the four-time champion if they were in the same car.

Vettel is the only driver other than Hamilton to win a race this season as Ferrari looks set to give Mercedes a run for their money this year. Asked if he was looking forward to a closer fight with Vettel, Hamilton said it would only be a true fight if they were in equal machinery.

"I'm looking forward to being able to have a fight with him on the track [this year], as well as with other drivers," Hamilton said. "I think ultimately you will never have a true race unless you are driving the same car, because there is always going to be differences in the cars. We might have more power but they might be better on the brakes, we might be better at one circuit but they might be better at another.

"I remember in the days of McLaren v Ferrari they had a slightly longer wheelbase and their car was better at looking after tyres - the rears in particular; theirs was a more was more of an understeering car whereas ours was an oversteering car; they were better on the medium to high-speed circuits and we were better on the medium to slow-speed circuits.

"It balances out over the year, but naturally if you are fighting it out with your team-mate it's a real battle because you've both got the same materials. The cars are getting closer and closer matched, so I'm looking forward to having that battle with not only Nico but now Kimi and Vettel."

Hamilton currently leads the championship by 27 points from team-mate Nico Rosberg and 28 points from Vettel.