The Swiss squad finished in seventh place in the constructors’ standings last year after scoring 44 points following a strong start to the season.
After a drop in performance during the middle part of 2011, Sauber managed to keep rival Scuderia Toro Rosso at bay thanks to two point-scoring results in the final races of the season, thus securing seventh position.
“Our goal is to finish regularly in the points so as to put ourselves in a significantly better position in the world championship,” said team boss Peter Sauber.
“We are looking forward to another season working with our young and talented drivers. Kamui will be competing in his third full season in F1. Last year we asked him to take on leadership responsibilities within the team and he has grown into the role.
“With his rookie season behind him Sergio is now approaching his second season, which is often the most difficult in a driver’s Formula 1 career. Both drivers have huge potential and will work with the same race engineers as in 2011 to continue developing that promise.”
The C31 continues with the trend set by other teams and it incorporates a stepped nose.
Unlike last year, the new Sauber features a pull-rod design for its rear suspension, allowing for improved packaging of the rear spring and damper elements.