Formula 1 is preparing for an important vote after concerns were raised about the new engine regulations.

According to BBC Sport, rivals believe Mercedes may have found a technical way to go beyond the allowed 16:1 compression ratio when the engine is running at high temperatures. The current rules say the ratio is measured at ambient conditions. However, Audi, Honda and Ferrari fear Mercedes has used thermal expansion and advanced materials, so the ratio could rise once the engine reaches operating heat.

A proposal has now been made to change the rule from 1 August. The compression ratio would also be measured at a “representative operating temperature” of 130°C. The vote will involve engine manufacturers, the FIA and Formula 1’s commercial rights holder. It is expected to pass.

If approved, Mercedes would have the first 13 races of the 24-race season under the present wording. Toto Wolff says the engine is legal and has FIA approval.

The compression ratio measures the difference in cylinder volume as the piston moves. Rivals believe exceeding 16:1 could be worth up to 0.3 seconds per lap. In Formula 1, teams watch each other like hawks, protect secrets like foxes, and react like lions when rules are unclear.

Williams boss James Vowles described the debate as “just noise.” Red Bull team principal Laurent Mekies said clarity is needed on what is allowed.

The issue was discussed during an F1 Commission meeting that also reviewed energy management and slower start procedures under the new power units.

The FIA said no immediate major rule changes are planned, but further evaluations will continue.