Ferrari looked set to win the season opener in Australia until a strategy blunder ended their chances.
Then at the first European round, in Russia, Vettel was taken out by then-Red Bull driver Daniil Kvyat
"Overall it has been a bit up and down season I think it could have been a lot better points-wise I think we didn’t manage to score enough points at the beginning of the year," he said.
Despite finishing behind Red Bull, Vettel feels that Ferrari did have the better car.
"Towards the end we have found ourselves in a very tight battle with Red Bull but I think overall we have had the stronger package and should have finished second in the constructors’ championship. Especially at the beginning we dropped too many points," he insisted.
"The big disappointment is that we didn’t manage to fight with Mercedes but nevertheless there have been a lot of things happen in the background which should make the team stronger for the next years," he added.
Bahrain International Circuit - Winter testing