Mercedes claim puts FIA ADUO ruling under pressure

Toto Wolff’s declaration after the Belgian Grand Prix that Mercedes has Formula 1’s “most powerful power unit” has reopened scrutiny of the FIA ruling that treated Red Bull as the benchmark on internal combustion engine performance and left Mercedes eligible for extra development.

The contradiction is at the center of the debate. Wolff, the Mercedes team principal, said in post-race coverage that Mercedes had the “most powerful power unit,” and he also acknowledged the team has “the best engine package.” Yet under the FIA’s Additional Development and Upgrade Opportunities system for the 2026 rules, Red Bull was judged to have the strongest ICE element, which meant it received no upgrade opportunities while Mercedes and other manufacturers got at least one token.

That distinction matters because the ADUO system measures only the combustion engine, not the full power unit. Wolff’s comments referred to the complete package rather than the ICE alone, but they still sharpened the obvious question: if Mercedes believes it has the strongest overall package, why is Red Bull the one locked out of development on the basis of benchmark engine performance?

Red Bull team principal Laurent Mekies, speaking to RacingNews365, did little to cool that argument. “I think Toto is right,” Mekies said. “I think they have the most power as well.” He added that Mercedes had “absolutely again a considerable advantage on the straight” at Spa and said it was “not the first weekend” Mercedes had shown that kind of edge.

Mekies also suggested Spa only made the gap easier to see. He said the effect was “just a little bit more due to the sensitivities of this track,” rather than something unique to Belgium, reinforcing the sense that Mercedes’ straight-line strength has been visible beyond a single event.

That is why Wolff’s remarks have become more than post-race confidence. Sky F1 pundit and former F1 driver Karun Chandhok said Red Bull should react immediately, arguing that “if I was Red Bull, my ears would just go, ping, and be straight on the phone to the FIA.” Chandhok said there were only two explanations: either Red Bull “genuinely have the best engine” or “they’ve lost a political battle” after Mercedes was granted the upgrade opportunity.

The pressure now is on timing as much as principle. Mekies pointed out that the second ADUO period closes in just over a week in Budapest, saying, “We will see what happens there.” With that deadline approaching, Mercedes’ public insistence that it has the strongest package only intensifies the focus on whether the FIA’s benchmark call will hold and whether Mercedes can keep developing while Red Bull cannot.