The FIA’s intervention
What was anticipated in recent days by the publication Motorsport Magazin has proven correct: yesterday, Friday, February 27, the International Federation published the amendment to the technical regulations and several articles were changed precisely because of the well-known affair relating to the compression ratio of Mercedes engines. The initial proposal – the one on which the online vote was based – namely the introduction from August 1st of a measurement at 130° of the compression ratio of the power units, in addition to the one at room temperature, has been superseded by a compromise reached between the FIA and engine manufacturers.
Here are the details of the revised technical regulation articles:
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Article C5.1.18
In the specific section dedicated to the power unit, a new point has been inserted, C5.1.18: “Treatment of numerical values: unless otherwise stated, all specific numerical values indicated in Article C5 shall be static values at room temperature“. Section 5 refers to the part of the regulations on engines: the intent to seal any other further gray areas is clear.
Article C5.4.3
Until yesterday, the article in question read: “No engine cylinder may have a generic compression ratio greater than 16:0. The procedure for measuring this value will be specified by each PU manufacturer based on the guidance document FIA-F1-DOC-C042 and performed at room temperature. This procedure must be approved by the FIA Technical Department and included in the manufacturer’s homologation dossier.”
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As of February 27, it has been modified as follows: “No engine cylinder, as indicated in point C5.1.3, may have a generic compression ratio greater than 16:0, measured under the following conditions:
– until May 31, 2026: when the engine is at room temperature
– from June 1, 2026, to December 31, 2026: when the engine is at room temperature and when the engine is at 130°C.
Any component, assembly, mechanism, or integrated arrangement of components designed or functioning to increase the compression ratio under operating conditions beyond 16.0 is prohibited.
The procedure that will be used to assess compliance with this article must be defined by each PU manufacturer according to the instructions detailed in document FIA-F1-DOC-042. This procedure must be approved by the FIA Technical Department and included in the PU manufacturer’s homologation dossier. (Note: document FIA-F1-DOC042 will be revised in accordance with the requirements coming into force on June 1, 2026, and consequently the procedure will be updated and the homologation dossier modified accordingly.”
The indications from the eve are therefore confirmed and the compromise decision taken in two stages: the current measurement at room temperature will be confirmed until May 31, 2026, and therefore until the Canadian GP (seventh race of the season), subsequently from June 1 (from the Monaco GP) and until the end of the world championship there will be both a cold and a hot measurement – at 130°C. From 2027 no indication, but from the whispers in the paddock there will be a new modification, and only the hot one should apply.
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