On Wednesday, Valtteri Bottas completed over a hundred laps at the Autódromo Hermanos Rodríguez during a Pirelli tyre test with Mercedes. The Finnish driver thus had one of his most intensive test days of the year, taking a significant step towards his Formula 1 return with Cadillac in 2026. Bottas currently serves as a test and reserve driver for the Silberpfeile, but will secure a permanent seat on the grid with the American racing team next year.
The tests in Mexico City were part of Pirelli’s development programme for the new tyres set to be introduced in 2026. Bottas took the wheel of a so-called mule car from Mercedes – a modified vehicle designed to mimic the aerodynamic load of the 2026 cars. The 35-year-old Finn primarily drove with the new C3 tyre, the most commonly used compound in the Pirelli range. Throughout the day, he completed 112 laps, well over one and a half times the race distance in Mexico.
Together with Mercedes junior Frederik Vesti, who accounted for 49 laps, Bottas collected valuable data for Pirelli. The tyre manufacturer is preparing for significant changes in the technical regulations of 2026. The 18-inch rims will be retained, but the tyres themselves will be smaller. They will be 25 millimeters narrower at the front and even 30 millimeters at the back. This means less grip and thus a new challenge for the drivers.
For Bottas, the test day also served as preparation for his return to Formula 1. In 2026, he will debut with the brand-new Cadillac team. While his future teammate Sergio Pérez will soon test a Ferrari for the Americans, Bottas is still under contract with Mercedes for the time being. However, he emphasizes that the German racing team is ‘not standing in his way’ with this transition. “I think Graeme (Lowdon, ed.) and Toto (Wolff, ed.) have spoken,” he previously told Crash.net. “Mercedes has been hugely supportive of this transfer, so I don’t expect them to block me in any way. There have already been discussions between me and Cadillac about what I can contribute, and everything is going fine.”
