Red Bull requests FIA review of ADUO results after emerging as F1 engine benchmark

During the Monaco Grand Prix weekend, teams and power unit manufacturers were all informed of the outcome of the first ADUO period – Formula 1’s catch-up mechanism with Additional Upgrade and Development Opportunities.

Red Bull Ford Powertrains emerged as the benchmark. According to the results, Mercedes’ internal combustion engine trails by between 2-4%, meaning the German manufacturer is entitled to one additional upgrade this year and one more next season.

Ferrari, Audi and Honda all fall into the category of being more than 4% behind on ICE power, which grants them two upgrades during the current season and two more in 2027.

Although these results are already widely known throughout the paddock, a public announcement from the FIA is yet to follow. This is despite the governing body initially stating that the results of the first ADUO period would be published no later than two weeks after the Canadian Grand Prix.

The reason is that one manufacturer – logically Red Bull – has requested an additional review. Autosport understands that this extra check is currently underway. The FIA began the process on Monday and it is expected to take between one week and 10 days.

Although Red Bull cannot formally lodge a protest against the ADUO outcome, the additional review is primarily intended to verify the results. The FIA will once again check whether all sensors are functioning correctly and whether all analysed data is accurate. Only once that has been confirmed will the results be officially released.

The real issues: discrepancy between measurement method and upgrades

While the additional review is a factual verification process, the issue with ADUO runs deeper.

There is a significant discrepancy between the measurement method and the upgrade opportunities that are linked to it. Only the internal combustion engine is measured, but once a manufacturer qualifies for ADUO, it is also allowed to modify electrical components such as the battery and MGU-K.

The current outcome has exposed that difference in the worst possible way. If the results prove correct, then Red Bull may have the strongest internal combustion engine, but the consensus in the paddock is that Mercedes still has the best overall power unit.

Under the current outcome, that dominant force would therefore receive the opportunity to improve its power unit even further, which was never the intended purpose of ADUO.

The issue lies in the measurement method, although FIA single-seater director Nikolas Tombazis has explained that all teams and manufacturers voted in favour of that approach themselves last year.

“In the spring of 2025 we had quite long discussions with them,” he said. “We offered whether we wanted to consider certain things like the turbo pressures, or the turbo diameters, or the plenum operating temperature and such. And the universal position by the PU manufacturers back then was that we should keep it simple.

“So the fact that it is the current horsepower measurement of the internal combustion engine has been appreciated right from the start. I would personally be quite open to the idea of complicating the parameters a bit, but that discussion was had more than a year ago and it was quite clear what it concluded.”

Nikolas Tombazis, FIA

Photo by: Kym Illman / Getty Images

A second issue is that ADUO creates room for a game of chess. Manufacturers are not allowed to stockpile upgrades, but the lead time required to introduce upgrades creates opportunities for strategic behaviour.

If Mercedes and Ferrari choose not to introduce all of their upgrades before the next measurement point – or even the one after that – Red Bull would logically remain at the top of the standings at the next assessment. As a result, Red Bull would once again be ineligible for additional development opportunities.

Although these shortcomings cannot be addressed in the short term, the FIA is at least investigating, at Red Bull’s request, whether the current results are factually correct before making them public.

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– The Autosport.com Team