Four-time world champion Sebastian Vettel has revealed that he was surprised by the unexpected form displayed by Ferrari last season but insisted the Italian manufacturers must improve every aspect of their car in order to maintain complete stranglehold over champions Mercedes in the 2016 season.
Vettel, who finished third in the Drivers' Championship standings behind Lewis Hamilton and Nico Rosberg, said that he was surprised by the final result of the team as he wasn't expecting such a strong season with Ferrari this year, News.com.au reported.
The German, who claimed three wins and one pole position in the 2015 season, insisted that they have to improve in a lot of areas, including aero and engine but added that the results of this season had shown that they were on the right path.
