No gifts in F1: Ferrari, Audi and Honda have written to the FIA about the advantages of the new Mercedes engine

While the Formula 1 has only just closed, the paddock is already in turmoil. Just a few months away from the major technical upheaval of 2026, a major controversy is stirring up the engine manufacturers. Ferrari, Audi and Honda have officially written to the FIA to ask for clarification on a technical solution developed by Mercedes, and adopted by Red Bull, which could offer a decisive advantage from the launch of the new regulatory era. In the background, an engine, an interpretation of the regulations... and a sporting balance that threatens to tip over even before the first Grand Prix.

The heart of the controversy

The starting point of this affair lies in the new 2026 engine regulations. To facilitate the arrival of new manufacturers and contain costs, the FIA has lowered the maximum compression ratio for internal combustion engines from 18:1 to 16:1. A constraint with far-reaching consequences, since this parameter has a direct influence on the power and efficiency of the power unit. Problem: this compression ratio is checked by the FIA when the engine is at a standstill, cold, under static conditions. It is precisely in this grey area that Mercedes is said to have built an innovative technical solution - or a controversial one, depending on your point of view.

Thermal expansion

According to several concordant sources, Mercedes has designed internal components capable of expanding with heat. At room temperature, the engine complies perfectly with the 16:1 ratio required by the regulations. But once the power unit has reached track operating temperatures, this expansion would reduce the volume of the combustion chamber, mechanically increasing the actual compression ratio. The potential gain evoked in the paddock is far from anecdotal. Estimates point to an extra 10 kW, or almost 13 horsepower. On the first simulations of the 2026 single-seaters, this would represent an advantage of between three and four tenths per lap, depending on the circuit. Such a gap could be enough to lock in a hierarchy from the outset.

Ferrari, Audi and Honda sound the alarm

Faced with this situation, Ferrari did not remain passive. The Scuderia, along with Audi and Honda, has sent a formal letter to the FIA seeking regulatory clarification. The issue at stake goes beyond the simple question of immediate legality: it's the ability to react that worries the automakers. The 2026 engines are already in an advanced validation phase. Modifying the architecture of the thermal unit to make up for such an advantage would require months of development, with an uncertain outcome. In the best-case scenario, a structural correction would not arrive until 2027, potentially dooming the 2026 season of those who had made a different technical choice.

Red Bull, the well-informed pupil

In this tense context, Red Bull appears to be the best-armed manufacturer. According to several revelations, the Milton Keynes-based team knew about this interpretation of the regulations several months in advance, thanks to an engineer who had moved from Mercedes to Red Bull Powertrains. This information would have enabled the team to work simultaneously on two engine architectures: one exploiting the aggressive interpretation of the compression ratio, the other remaining strictly within the 16:1 limit even at high temperatures. This dual approach gives Red Bull a strategic security that Ferrari, Audi and Honda do not have.

If the controversy has reached such proportions, it's also because it places the FIA in an extremely delicate position. According to the specialist press, Mercedes has been in regular contact with the FIA throughout the development of its 2026 power unit, receiving reassuring signals about the conformity of its solution, particularly with regard to compression ratio control procedures.

To change the interpretation of the rules today would expose the FIA to heavy criticism, and even legal consequences. But officially validating this solution would mean accepting that an engine could respect the rules at a standstill while circumventing them in real race conditions. A dangerous precedent, which would contradict the fundamental principle that a single-seater must comply with the rules at all times during a Grand Prix weekend.

A 2026 championship already under tension

With just a few months to go before the start of the season and the new regulations, Formula 1 faces a major dilemma. One thing is certain: at the end of 2025, there are no presents under the tree in Formula 1. The 2026 championship has already begun... and it's being played out as much in the FIA's offices as in the engine manufacturers' factories.