Mercedes Formula 1 team principal Toto Wolff has called on rival power unit manufacturers to "just get your s*** together" after they voiced complaints to the FIA on Mercedes' interpretation of the regulations.
The 2026 power unit regulations prescribe an engine compression ratio of 16:1, down from 18:1 last year. That compression ratio has always been measured at ambient temperatures when the engine isn't running, so it doesn't account for any material expansion under heat when cars are running out on track.
