Formula 1 is facing a potential engine controversy as the FIA has called an emergency meeting with engine manufacturers on January 22 to discuss concerns surrounding Mercedes' and Red Bull's 2026 power units. The heart of the issue lies in the interpretation of the 2026 engine regulations, specifically those pertaining to the compression ratio within the internal combustion engine (ICE).

The 2026 regulations stipulate a maximum compression ratio of 16:1, a reduction from the previous 18:1 limit. This change aimed to control performance, improve fuel efficiency, and encourage new manufacturers to enter the sport. However, it has been suggested that Mercedes, and to a lesser extent Red Bull, have discovered a loophole that allows them to exceed this limit under race conditions.

Reportedly, Mercedes has engineered a system that complies with the 16:1 limit when engines are measured at ambient temperatures, but cleverly exploits thermal expansion to increase the compression ratio to nearly 18:1 once the engine reaches operating temperatures on the track. This could lead to a performance gain of around 15 horsepower, potentially translating to a significant advantage of 0.3 to 0.4 seconds per lap, depending on the circuit.

Rival engine manufacturers, including Ferrari, Audi, and Honda, are reportedly unhappy with this interpretation of the regulations. They argue that any engine exceeding the 16:1 compression ratio at any point during competition should be deemed illegal, citing Article C1.5 of F1's technical regulations. These manufacturers have reportedly sent a joint letter to the FIA seeking clarification and stricter action.

The FIA, initially appearing satisfied with the Mercedes approach, has now called a meeting to address these concerns and ensure that the regulations are understood and applied consistently across all participants. An FIA spokesperson stated that these discussions are customary during the introduction of new regulations.

The outcome of this meeting could significantly shape the competitive landscape of the 2026 season. If the FIA deems Mercedes' interpretation legal, it could trigger protests from rival teams at the season-opening Australian Grand Prix. Conversely, if the FIA changes the regulations mid-season, it risks a legal challenge from Mercedes. A compromise could involve allowing Mercedes to use the system only in 2026 if they commit to abandoning it for 2027.

The situation is further complicated by the fact that Mercedes-powered teams, including McLaren, Williams, and Alpine, could also benefit from this alleged loophole. With potentially eight cars on the grid enjoying a power advantage, the concern among rival manufacturers is escalating.

Red Bull's position in this dispute is somewhat neutral, as they have also reportedly explored similar concepts. However, they have not been as successful as Mercedes in replicating the same effect.

The FIA faces a major dilemma. Outlawing the system could severely handicap Mercedes, while allowing it risks political fallout and undermines the competitive objectives of the new regulations. The January 22 meeting will be crucial in determining the future of the 2026 F1 season and how the FIA handles technical innovation within the framework of its regulations.