Mercedes receive robust defence over F1 power unit legality

Former Formula 1 driver Juan Pablo Montoya has robustly defended the legality of Mercedes’ power unit, at a time when rivals have raised serious questions.

The 2026 power unit regulations stipulate a mandatory compression ratio of 16:1, which the Silver Arrows comply with in order to pass the necessary grand prix tests.

Crucially, these tests conducted by the FIA take place when a power unit is at ambient temperature, potentially opening the door for the rules to be bent.

It is believed Mercedes’ engine is capable of operating with a compression ratio of 18:1 while on track, giving the W17 better efficiency through low- and medium-speed corners.

While motorsport’s governing body has deemed the Brackley-based team’s engine legal, it has announced new power unit tests to be introduced from June 1.

The new tests will see the FIA start checking compression ratios at 130°C, eliminating any Mercedes advantage if it is running at 18:1, as this would then become detectable.

Essentially, this will force all teams to run a 16:1 ratio to pass the checks. In Montoya’s eyes, Mercedes’ rivals are wrong to complain, stressing that what makes F1 great is the technical ingenuity involved in finding ways to work around the rules.

Asked what he makes of Mercedes' rivals questioning the legality of its power unit, Montoya exclusively told RacingNews365: "For me, it’s kind of crazy to say that it’s not in the rules. 

"If the rule says [you need to] measure at this temperature and you go and measure at that temperature, and the engine is [deemed] legal, that’s what the rule says. 

"That’s the beauty of F1: finding ways to bend the rules, finding ways to do it better than anybody else, and finding things that nobody else can do. 

"And if you’re complaining about that, instead of complaining, why don’t you try to do it yourself?"