Formula One's governing body, the FIA, has approved amendments to the 2026 engine regulations following a dispute involving Mercedes over compression ratios. The changes, passed unanimously by an e-vote of the World Motor Sport Council, aim to close a suspected loophole that may have given Mercedes a performance advantage.
The controversy centres on the compression ratio limit of 16:1, measured in cold conditions. While all engines comply with this measurement, Mercedes is suspected of exploiting thermal expansion to increase the ratio when the engine is hot, potentially gaining a significant edge. Mercedes has denied any advantage and stated the rule change will make no difference to them.
Under the compromise, the compression ratio will be controlled in both hot and cold conditions from 1 June 2026, and solely under operating conditions from 2027 onwards. The FIA had initially proposed a stricter test at 130 degrees Celsius from 1 August, which would have covered more than half the season.
The FIA acknowledged that the 2026 regulations represent one of the biggest changes in recent memory, and that collective learnings from pre-season testing and early rounds are expected. Additional amendments to sporting and financial regulations were also approved.
Meanwhile, F1 is monitoring the situation in the Middle East after missile strikes on Iran. The season opener in Australia is expected to go ahead as planned, but Bahrain and Saudi Arabia, hosting rounds four and five in April, are under review.
