Have Mercedes and Red Bull discovered a clever loophole in the engine compression ratio? Now former team boss Christian Horner is also commenting on the matter.
The first race of the 2026 Formula 1 season hasn’t even been run yet, but the first controversy is already brewing: Have Mercedes and Red Bull discovered a loophole to circumvent the new engine regulations? Unofficially, it is said that both teams are cheating on the compression ratio.
Background: The compression ratio was reduced from 18:1 to 16:1 for the new season, partly because this value is supposed to be easier for new manufacturers to achieve. However, Mercedes and Red Bull are said to have taken advantage of the fact that the ratio is only measured when the vehicle is stationary and at ambient temperature.
Rumor has it that the compression ratio for the aforementioned teams rises back to 18:1 while driving and at operating temperature, which would be a clear performance advantage. This is because, as a general rule, a higher compression ratio ensures better thermal efficiency.
Former Red Bull team boss: “You have to push the limits”
Meanwhile, former Red Bull team boss Christian Horner, who was instrumental in getting the new engine deal with Ford off the ground, has also commented on the allegations. “Formula 1 is all about testing limits,” the Briton explains in a recent interview with Today.
“It’s about how you interpret the rules. It’s always been that way, and it always will be.” Horner skillfully sidesteps specific questions about whether there could be any truth to the rumors. “The teams that are the most conservative are never at the front of the field. You have to push the limits.”
“And of course, it’s about how you interpret the rules, and engineers—some of the smartest engineers in the world—will look at those rules and think, ‘Okay, how can I maximize performance?’” smiles the long-time Red Bull team boss.
Mercedes team boss makes it clear: “Power unit is legal”
Mercedes team boss Toto Wolff, on the other hand, cannot understand the criticism from the competition. “I just don’t understand why some teams are focusing more on the others and continuing to make a case that is actually very clear and transparent,” the Austrian emphasized at the official launch of the W17.
“Communication with the FIA has been very positive throughout, and it’s not just about the compression ratio, but other things as well. In this area in particular, the regulations are very clear. It is very clear which standard procedures apply to all engines, even outside of Formula 1.”
“So get your act together,” Wolff said clearly, rejecting any blame: “The power unit is legal. The power unit complies exactly with the regulations. The power unit complies exactly with the tests as they are carried out.”