The C31 chassis was designed by James Key, Matt Morris, Pierre Waché, and Willem Toet, again using a customer Ferrari V8 engine. The car carried substantially more commercial sponsorship than its predecessors, reflecting the growing Mexican investment brought by Pérez and reserve driver Esteban Gutiérrez. Partners included Claro, Telcel, Telmex, Tequila Cuervo, Visit México, Oerlikon, NEC, and Certina.
The C31 proved to be the most competitive Sauber car of the early 2010s Ferrari-era partnership. Pérez scored the car's first podium at the Malaysian Grand Prix, followed by a second podium — another third — at the Canadian Grand Prix, where Kobayashi also finished ninth to support the team's push up the Constructors' standings.
The German Grand Prix delivered the C31's best single-round points haul. Kobayashi finished fifth before a post-race penalty for another driver promoted him to fourth, with Pérez sixth, giving Sauber 20 points in a single round — their best such result since returning to the grid as a privateer.
The Belgian Grand Prix at Spa-Francorchamps set the context for one of the season's most dramatic incidents. Kobayashi and Pérez qualified second and fourth respectively, the best combined grid positions in Sauber's history. At the race start, Romain Grosjean's Lotus triggered a first-lap collision that eliminated Pérez, championship leader Fernando Alonso, and Lewis Hamilton. Kobayashi's car was also damaged in the incident, dropping him through the field to thirteenth.
Pérez recovered to deliver his finest race of the season at the Italian Grand Prix at Monza. Starting on a contrasting tyre strategy — hard compound tyres switching to medium on lap 30 of 53, opposite to many front-runners — he worked through the field past Michael Schumacher, Kimi Räikkönen, Nico Rosberg, Felipe Massa, and Alonso to finish second, his third podium of the season. Kobayashi accompanied him in ninth. The double points haul of 20 matched the German weekend result.
The C31 closed 2012 sixth in the Constructors' Championship with 126 points — widely noted as the highest total achieved by a privateer Formula One team since 1993. The car took two fastest laps (China and Monaco), four podiums (Malaysia, Canada, Italy, and Japan), and placed in Q3 on thirteen occasions.
Following its racing life, the C31 served Sauber as a development tool for junior programme evaluation. Former IndyCar driver Simona de Silvestro tested the C31 at the Fiorano Circuit, owned by Ferrari, during her association with the team. Young drivers Adderly Fong and Roy Nissany also tested the car over two days at Circuit Ricardo Tormo, completing 99 laps in total across both days with Fong driving on the first day and Nissany on the second.
The Sauber C31 stands as one of the most successful cars produced by the team in the post-BMW privateer era. Its 2012 performance — four podiums, sixth in the Constructors' Championship, and a points total not matched by a privateer in nearly two decades — confirmed that Sauber's Ferrari-powered package, combined with Pérez's driving in particular, could challenge the established midfield hierarchy. Pérez's Monza result, achieved through strategic differentiation rather than raw pace advantage, was widely regarded as one of the season's most accomplished drives from outside the top teams.