THE FIA has proposed a mid-season rule change after arguments over the legality of Mercedes’ engine ahead of the 2026 campaign.

The issue, which centres around compression ratio limits, has dominated talk during pre-season with rival manufacturers Ferrari, Red Bull, Honda and Audi suggesting Mercedes had found a loophole which allowed them to deliver a higher limit when their engine is at operating temperature.

Mercedes boss Toto Wolff admitted ahead of a meeting in Bahrain today that he was confused as to how it had become such a big talking point.

His team — and those that also run Mercedes engines including McLaren and Williams — will be permitted to start the season with the current engine but a vote will take place over whether a regulation change should be implemented from August onwards.

For the change to come into force a “super majority” would be needed, requiring six votes out of seven — the five engine manufacturers plus the FIA and Formula One.