Formula One's governing body and manufacturers have agreed on a compromise to resolve an engine controversy. The dispute, centered on engine compression ratios, threatened to overshadow the season's start in Australia.
The sport is set for significant engine and chassis regulation changes in 2026. Mercedes was suspected of exploiting a loophole related to thermal expansion for performance gains, leading to potential protests.
The FIA announced unanimous approval of amendments to the 2026 Formula One regulations. The compromise dictates that compression ratios will be controlled in both hot and cold conditions from June 1, 2026, and subsequently only in operating conditions from 2027.
Mercedes supplies engines to McLaren, their works team, Williams, and Alpine. Other manufacturers include Red Bull, Audi, Honda (for Aston Martin), and Ferrari (supplying Haas and Cadillac).
Regulations limit engine compression ratios to 16:1 in cold conditions. The concern was that Mercedes found a way to increase this ratio when engines operate at high temperatures.
The FIA acknowledged collective learnings from pre-season testing and initial races due to the substantial regulatory changes, with ongoing technical checks on energy management.