Valtteri Bottas got back behind the wheel of a Formula 1 car this week, completing 112 laps at the Autódromo Hermanos Rodríguez in Mexico City during a Pirelli tire test with Mercedes. The Finnish driver is continuing to prepare for his return to the grid in 2026, when he will form a partnership with Sergio Perez at the new Cadillac team.
The test was part of the development program for the tires that will be used in the 2026 season. Bottas shared the workload with Mercedes junior driver Frederik Vesti, using a ‘mule car’ provided by the Brackley-based team.
During the day, Bottas focused primarily on the new C3 compound, the most versatile in Pirelli’s range, completing long sequences of laps equivalent to more than a race and a half. Vesti, on the other hand, completed 49 laps in series of 10 laps each, contributing to the collection of data.
The changes to the tires for 2026 will be significant. Although the 18-inch wheels will remain, the width of the tires will be reduced, with 25 mm less at the front and 30 mm at the rear, which should alter the behavior of the cars and the level of grip available.
The test in Mexico may have been Bottas’ last with Mercedes, although, according to information from PlanetF1.com, no final decision has been made about his participation in future sessions. Prior to this, he had already conducted private tests with McLaren in March and with Mercedes itself in Jerez in July.
Pirelli will conclude its 2025 testing schedule in Abu Dhabi on December 9, two days after the end of the current season.
