FIA allows Mercedes to keep using F1 engine trick until August

The FIA has recently launched an e-vote primarily centered on a proposed change to the assessment of the power unit compression ratio in running condition. There has been a big uproar over Mercedes’ ability to increase their compression ratio from 1:16 to 1:18 when the engine is running hot.

Over recent weeks and months, the FIA and the Power Unit Manufacturers have collaboratively developed a methodology to quantify how the compression ratio changes from ambient to operating conditions. Following validation of this approach, a proposal has been submitted whereby, from 1 August 2026, compliance with the compression ratio limit must be demonstrated not only at ambient conditions, but also at a representative operating temperature of 130°C.

After the engine meeting in Bahrain Wednesday, Toto Wolff (R) thanked FIA President Mohamad Ben Sulayem (L) for letting Mercedes continue to use their ‘trick’ engine until August 1st.

The vote has been submitted to the Power Unit Manufacturers, and its outcome is expected within the next 10 days and will be communicated in due course. As with all Formula 1 regulatory changes, any amendment remains subject to final approval by the FIA World Motor Sport Council.

The compression ratio saga has been addressed with a change planned for August 1 if approved – before round 14 at Zandvoort. Thus the Mercedes Power Unit can run as is until then.