Lewis Hamilton has suggested that a championship challenge from Ferrari in 2016 will be good for Formula 1.
The Scuderia have been the closest team to Mercedes in the constructors' championship, but the Silver Arrows have already secured their second successive title with four races to spare.
However, Hamilton is hoping that Ferrari provide a strong test for Mercedes in 2016.
He told Autosport: "Sebastian (Vettel) is always going to be one of the strongest opponents, but it depends how you look at it.
"As a driver from another team he's definitely going to be the strongest opponent, but Nico [Rosberg] will come strong next year, but of course I hope we do have a race with the Ferraris, I think it would be good for the sport.
"Hopefully it will be with us being in front, but still a good race."
Hamilton leads the drivers' championship by 66 points from Vettel.
