2026 is set to mark the start of a new era in Formula 1, accompanied by a significant regulation overhaul. Teams have been preparing for this season ever since 2024, and the development of the engines has been the primary focus for each manufacturer.
Throughout 2025, Mercedes were rumored to have developed the strongest engine coming into the 2026 season. As we approached pre-season, news emerged that Mercedes had discovered a potential loophole in the regulations, where their compression ratio varies between standard and hot temperatures.
The expanded ratio allows for a minor boost in horsepower, reportedly resulting in a gain of a few tenths of a second per lap. In Formula 1, such a difference can have a massive impact.
However, other engine manufacturers have voiced their opposition to the discovery and are calling for a change to how compression ratios are measured. The FIA have also taken a significant interest in the subject and plan to investigate to determine the next course of action.
Since Mercedes did not violate the regulations as they are currently written, it is still unclear whether any potential alterations would go into effect in 2026 or 2027.
But changing the regulations for 2026 would be a massive mistake.
Mercedes took a smart approach toward their engine development while staying within the regulations. They cannot necessarily be blamed for taking advantage of the FIA not writing the regulations with complete clarity.
If the FIA were to change how the compression ratios are measured, potentially doing so under hotter conditions, Mercedes would be beyond the 16:1 limit. Any change to the regulations would impact four teams on the grid, including two that are expected to battle at the front in McLaren and Mercedes.
Given the fact that one round of pre-season testing is already done and another is underway, it would be nearly impossible for Mercedes to alter their engine so that the compression ratio stays within the 16:1 limit. It would be a bad look for the sport where two top-tier teams are hindered this close to the first race of the year.
The best course of action, and the most logical one, would be for the FIA to maintain the legality of the Mercedes engine while making some minor changes to the clarity of the regulations for 2027. It is a compromise that could appease Ferrari, Audi, and Honda, while keeping Mercedes and their customer teams satisfied for the time being.