Fernando Alonso believes 'favourites' Mercedes can be defeated in 2015 F1 season

Two-time world champion Fernando Alonso believes that Mercedes will not be able to replicate last year's success despite being tipped as the favourites to win the upcoming Formula One season.

Mercedes dominated 2014 season as they won 16 out of 19 races, with Lewis Hamilton crowned as the World Champion.

Tipping Mercedes as favorites, Alonso said that Mercedes have an advantage in performance, at least to start the season, adding that they have the continuation of a dominant car, so it is a little bit easier than for them who have a new power unit, Sport24 reported.

Reflecting on McLaren's chances, the Spaniard further said that they have a very streamlined, aggressive car design and he didn't think that Mercedes would win so many races this year as all the other teams are closer than last year, the report added.

Jerez pre-season test saw four-time world champion Sebastian Vettel topping the time sheet and the McLaren driver finishing over 18 seconds behind the German.