Formula 1's governing body faces delays in publishing ADUO results after Red Bull Ford Powertrains requested an additional review of the findings. The benchmark emerged during Monaco Grand Prix weekend, with Mercedes' internal combustion engine trailing by 2-4% and Ferrari, Audi and Honda falling more than 4% behind. This grants Mercedes one upgrade this year and next, while the others get two upgrades each season.

The review process began Monday and will take one to ten days, focusing on sensor functionality and data accuracy. Teams already know the outcomes, but public confirmation awaits the FIA's verification. While Red Bull cannot formally protest, the request aims to confirm results before official release.

A deeper problem exists with ADUO's measurement methodology. Only the internal combustion engine gets measured, yet qualifying manufacturers can modify electrical components like batteries and MGU-K. This creates a mismatch where the strongest ICE doesn't necessarily represent the best overall package.

McLaren's Oscar Piastri and Red Bull's Isack Hadjar have both been affected by power unit disparities this season. The strategic element compounds issues—manufacturers can delay upgrades to remain eligible for development opportunities, potentially keeping Red Bull atop future standings despite having the weakest overall unit.