Valtteri Bottas says Williams needs to step up in 2016 and develop a stronger all-round car than this season.
Williams was Mercedes' nearest challenger last year, and while Ferrari has moved ahead in the pecking order this season, it remains a regular podium challenger. However, after struggles on high downforce tracks, Bottas - who has been retained by Williams for 2016 - says next year's car cannot afford to be weak on certain circuits.
"One important thing is that we can’t have bad tracks for us, we need to be strong everywhere if we want to score good points consistently and we want to challenge we need to be quick everywhere," Bottas said. "We should have been better prepared for Spa, maybe by making a Spa aero package like many other teams did.
"I think that’s the main thing and we need to be more reactive to different types of tracks, because now we have the good tracks for us that we pin our hopes on, but that’s not enough if you want to win."
And Bottas believes the stability offered by retaining the same driver line-up will help him and Felipe Massa push Williams in the right direction.
"I think for me it’s the best place to be at this point. Obviously not many seats are available anyway and for me it is natural to stay with the team. Continuity is good for the team and having the same team-mate in Felipe. We already have a good base and we can start working for even better results."