The C45 made its public debut at
Bahrain International Circuit during official preseason testing. Prior to the car's debut, both drivers completed testing under the Testing Previous Cars (TPC) programme with the C44 at
Yas Marina and the C42 at
Circuit de Barcelona-Catalunya.
Debut and first points On its race debut at the
2025 Australian Grand Prix, Bortoleto reached Q2 in qualifying and Hülkenberg finished in seventh position to score six points. As a result, the C45 achieved more points in its first race than its predecessor scored throughout the entire 2024 season. After
Jonathan Wheatley joined as Team Principal for the
Japanese Grand Prix, the team's pit stop times began to drop substantially. After recording the second and fourth-fastest stops in Bahrain, the team recorded the fastest pit stop in
Miami with a time of 2.24 seconds. However, the team still failed to score points for seven consecutive races, which included a post-race plank wear disqualification for Hülkenberg after
Bahrain.
Mid-season upgrade packages Sauber brought a large upgrade package to the Spanish Grand Prix, which included substantial changes to the floor outer edge, the engine cover shape, and the front wing. Aimed at reducing the car's sensitivity to dirty air and crosswind, Hülkenberg drove from fifteenth on the grid to sixth after passing Lewis Hamilton's Ferrari in the closing laps. After post-race penalties were applied the team recorded a fifth place finish, its best result since the
2022 Emilia Romagna Grand Prix. Hülkenberg finished in the points again with eighth in
Canada, however Bortoleto still failed to score. This changed after a second upgrade package was introduced in
Austria, where Bortoleto qualified eighth to deliver the team's first Q3 appearance since 2023. In the race, Bortoleto led the team's first double points finish since 2023, finishing in eighth and winning driver of the day. A third upgrade package in four races was introduced in
Great Britain, which included further changes to the C45's floor and the front wing. During a mixed-condition race with heavy rain, Hülkenberg held off Lewis Hamilton in the final stages to finish on the podium in third position. This result was his maiden podium after 239 Formula 1 starts, ending the longest historical streak of race starts without a podium finish. This was also the team's first podium in thirteen years, ending a drought dating back to the
2012 Japanese Grand Prix. ==Sponsorship and livery==