F1: FIA breaks silence on compression ratio trick, with explanatory video

As the 2026 season of Formula 1 tension is mounting behind the scenes. After several weeks of rumours, protest letters and technical speculation, the FIA has decided to speak out. And not just with a press release: the governing body has published a long video explaining the changes to the 2026 regulations, in which it tackles head-on, at the very end, the hot topic of the moment: the compression ratio of future V6 hybrids. It's an eagerly-awaited passage, as this issue is currently crystallizing tensions between engine manufacturers on the eve of a major regulatory change.

Compression ratio at the heart of the 2026 controversy

In the video, the FIA's technical managers start by going back to basics. The compression ratio, they remind us, is one of the most basic parameters of a four-stroke internal combustion engine: it corresponds to the ratio between the volume of the air-fuel mixture drawn into the cylinder and the volume at which this mixture is compressed before ignition. The higher the ratio, the more efficient the engine... up to a certain limit. Excessive compression leads to undesirable phenomena, such as pre-combustion or knocking, which are destructive to the engine. It is precisely to avoid these problems that the 2026 regulations lower the compression ceiling from 18:1 to 16:1. A figure presented by the FIA as a compromise, more accessible to new entrants.

A rule designed to attract new engine manufacturers

The FIA fully endorses this approach. In its view, without technical simplification and a reduction in extreme requirements, Formula 1 risked ending up with just two engine manufacturers in the medium term. Conversely, the new regulatory framework has secured five powertrain manufacturers, with a sixth on the way. But this openness also has its downside. As the body itself acknowledges, some engineers quickly identified a grey area: an engine that was perfectly compliant during cold testing could, once brought up to operating temperature, display an actual compression ratio higher than the theoretical limit. It is precisely this point that has triggered the current storm.

FIA admits possible "interpretation" on the spot

For the first time publicly, the FIA acknowledges in this video that technical solutions do exist for changing the compression ratio when the engine is hot. Without ever explicitly quoting Mercedes, the body confirms that "some people have found ways of potentially increasing this parameter when the engine is running at high temperature". A statement that indirectly validates the concerns now expressed by Ferrari, Audi and Honda. joined by Red Bull Racing. The FIA is not talking about cheating, but about an unanticipated interpretation when the rules were drawn up. A classic of modern Formula 1.

Putting out the fire before Melbourne

The central message of the video, however, is clear: the FIA wants to resolve this problem before the start of the season. According to those in charge, there is no question of launching the new technical era under the sign of controversy, protests or legal recourse. The stated aim is simple: to develop testing procedures so that they better reflect actual engine operating conditions, particularly when hot. It's a way of closing the door on interpretations without, at least on the surface, radically altering the text of the regulations. At the same time, the FIA recognizes the dilemma it faces: to delay would be to cast doubt on sporting fairness, but to act too abruptly could expose the body to accusations of changing the rules midstream.

One thing's for sure: while the subject of compression ratio now seems to be on the way to resolution, the FIA itself warns that other technical debates will inevitably arise in the months to come. The 2026 season hasn't even begun... and it's already making headlines like no other.