The new rule on the compression ratio comes into force today: what changes

The arrival of June marks the entry into force of the new procedure for checking the compression ratio of the internal combustion engine, a novelty which mainly affects Mercedes-powered ones. This is an issue that continues from last year and will have further implications in 2027, when the cold test will disappear completely. The Brackley team does not seem worried, the FIA ​​ensures that the gain guaranteed by the solution is minimal and even the competition has little hope in the change, but only the track will give the final verdict. What changes As established by the additions to the technical regulations approved last February, from 1 June a second procedure for checking the compression ratio will debut, one of the most important parameters of the internal combustion engine, which indicates how much the pistons compress the air-fuel mixture in the cylinders. In addition to the test performed at room temperature, the maximum value of 16 will now also have to be verified through a measurement at 130°C. It will be the responsibility of individual engineers to design the procedure, following the instructions described in an official document, with subsequent approval by the FIA. Added to all this is another novelty. The new rule also explicitly states that any “component, assembly, mechanism or arrangement of integrated parts designed or functioning to increase the compression ratio in operating conditions above 16 is prohibited”. Mercedes’ opponents, however, believe that keeping the test at room temperature is an advantage for the championship leaders. In fact, the competition will not be able to modify their engines to start from a higher compression ratio when cold which then stabilizes at 16 once operating temperatures are reached. To do this we will have to wait until 2027, when room temperature verification will completely disappear from the regulation. Photo by Mark Sutton – Formula 1/Formula 1 via Getty Images A long saga The changes in June are just the latest step in a long series of events that began last autumn. Mercedes took the Federation by surprise by finding a way to control the evolution of the compression ratio as the engine temperature increased. In October the FIA ​​clarified an initial ambiguity in the regulation on the issue, specifying that the compression ratio measurements would be carried out at room temperature, as per practice in the automotive industry. A further note appeared in February, clarifying that all numerical values ​​in the engine section of the regulation, including the compression ratio, are static references at room temperature, unless otherwise specified. On the same occasion, the Federation defined the new rule valid from 1 June, which provides for the introduction of a second test at 130°C and the explicit prohibition of solutions that increase the compression ratio. Speaking to the press, Nikolas Tombazis, director of the FIA ​​single-seater department, commented on what Mercedes had done, defining it not as something wrong or a cheat, but stating that “perhaps it was outside the normal intentions of the regulations”. Again according to the Greek engineer, the Federation’s subsequent intervention served to avoid encouraging the entire Formula 1 to invest in exotic materials or other solutions that according to the organizers would have gone against the spirit of the sport. Effects to be evaluated On the eve of the Miami Grand Prix, Tombazis ensured that the advantage of the Mercedes engine solution was minimal, relegating the media hype on the issue to a case of collective hysteria. The Brixworth engineer himself doesn’t seem particularly worried and neither does the competition has high hopes in the introduction of the hot test, but only the track can provide the proof. Monte Carlo has always been an atypical event that places little emphasis on engines, which is why the event circled on the calendar is the Barcelona Grand Prix. Click here to add as a favorite source on Google Discover: you will find our content more easily!

Automobile Magazine – F1 English News , 2026-06-01 16:00:00