F1 | FIA rules on the alleged Mercedes and Red Bull engine loophole. The FIA has discussed the alleged Mercedes and Red Bull engine “trick” for 2026.

The FIA has now addressed the controversy surrounding the alleged Mercedes and Red Bull Ford engine “trick” for the 2026 Formula 1 regulations, but without delivering a definitive verdict.

Ferrari, Audi and Honda emerged with few certainties from the latest discussions on the 2026 power units. During the meeting held on Thursday between the eleven Formula 1 teams and the FIA, no decision was taken to ban the alleged solution used by Mercedes and Red Bull Ford on their own cars and those of their customer teams.

According to information gathered through direct contacts with individuals involved in the discussions, the topic was only added to the agenda recently and was handled with considerable caution. At the heart of the debate is the compression ratio, which the regulations cap at a maximum of 16:1. This value is well known to all manufacturers, as a higher compression ratio generally translates into greater efficiency and improved engine performance.

The FIA’s position on the Mercedes and Red Bull engines

In recent months, speculation has emerged that Mercedes, later followed by Red Bull Ford, may have developed a solution that allows for a higher effective compression ratio while still formally remaining within the regulatory limits.

According to paddock rumors, the compression ratio is measured when the engine has not yet reached its operating temperature. Once the power unit heats up, certain internal components would expand, bringing the piston closer to the top of the cylinder. This behavior would effectively increase the compression ratio during on-track use, improving performance while also reducing fuel consumption.

This scenario triggered a strong reaction from Ferrari, Audi and Honda. The three manufacturers believe that this interpretation of the regulations does not align with the spirit of the rules and have called for a clarifying intervention from the FIA. However, Thursday’s meeting did not produce any immediate decisions. The discussion focused more on potential future regulatory adjustments rather than on reinterpreting the current rules.

According to reports from GPBlog, any potential ban on the alleged workaround would not come before the start of the new season. Mercedes and Red Bull Ford remain convinced that their solutions fully comply with the regulations, while Audi continues to express concerns and reservations.

For rival manufacturers, the issue is also procedural. Without the ability to directly inspect competitors’ engines, it becomes extremely difficult to lodge a formal protest based on concrete evidence rather than on paddock speculation.

Although no major announcements emerged from the meeting, the matter is far from closed. The prevailing feeling in the paddock is that the issue could resurface in the coming months, especially as the debut of the new power units draws closer. The 2026 engine chapter therefore remains open, with technical and political balances likely to have an impact both on and off the track.