F1 2026 pre-season testing: Formula 1 moves to close engine loophole that Mercedes is accused of exploiting

Mercedes team principal Toto Wolff insisted that their engine was legal and that its design had been approved by the FIA.

Compression ratio is a measurement of the cylinder displacement between the two ends of the piston stroke. Competitors believe that increasing this ratio beyond 16:1 could give a gain of up to 0.3 seconds per lap.

Williams team boss James Vowles, whose team uses Mercedes engines, dismissed the controversy as “just noise that will probably go away in the next 48 hours”.

Red Bull’s position on the compression ratio argument is not clear yet, after its entry as a power unit manufacturer this season.

“We don’t think this is hype. We think we have to have clarity about what we can and cannot do,” Red Bull team principal Laurent Mekes said on Wednesday.

The new engine proposal came on the same day that the Formula One committee discussed a variety of issues arising from the first running of the cars under the new rules introduced this year.

This included the increasing difficulty of the starting process and the way in which energy deployment and recovery is controlled by rules.