Political power play in F1: Why Mercedes also backed the FIA decision

Ferrari, Audi, and Honda were furious. They accused Mercedes of illegal practices with the new power unit, claiming it had managed to achieve a higher compression ratio and thereby generate extra performance.

Here’s how: the regulations state that the compression ratio may not exceed 16:1. Their power unit would have components that expand once the engine is warm, pushing the piston closer to the top of the cylinder than when the engine is cold. This raises the compression ratio, delivering extra performance and lower fuel consumption.

Since the FIA initially did not measure the ratio under operating conditions, Mercedes would have an extra advantage—at least, that’s what the complaining manufacturers believed. They feared being at a disadvantage compared to the Mercedes teams from the get-go.

What followed was Formula 1 in its purest form. After months of haggling over the measurement method, a compromise has now been reached that doesn’t hurt Mercedes at all and seems solely intended to give the complaining teams an easier way to catch up in 2027.

Starting June 1, the compression ratio will be checked not only at ambient temperature but also under operating conditions. At first glance, this seems like a disadvantage for Mercedes, as they would have to modify their engines.

In reality, it’s not that bad. The new measurement method simply allows other manufacturers to build engines with a higher compression ratio at ambient temperature. This enables them to neutralize any perceived advantage so they can pass the test under both operating and ambient conditions with the 16:1 compression ratio.

In other words: this is an expedient political compromise, making it easier for Ferrari, Audi, and Honda to build an improved power unit for the 2027 season, while Mercedes can continue along its chosen path.

To make all the recent uproar even more remarkable: Mercedes already complies with all the proposed tests that will apply from June 1. The German manufacturer therefore does not have to change anything in the coming months.

Undoubtedly, that was also the reason Mercedes voted in favor of the late rule change, as the FIA’s statement on the vote noted — simply because it didn’t matter to the manufacturer anyway.

All in all, the fuss over the compression ratio has become a fine example of how politics works in Formula 1.