Mattia Binotto suggests Mercedes may have masked power to exploit F1 development rules. F1 ADUO controversy: Binotto explains why Mercedes may have concealed its engine potential.

Although tensions have eased in recent weeks, partly because of Red Bull’s request for the FIA to review the data used to compile its engine performance rankings, the ADUO system remains one of the hottest topics behind the scenes in Formula 1. Following disagreements between manufacturers over the ADUO results, Audi Team Principal Mattia Binotto has urged the sport to reconsider the methodology used by the FIA to determine which engine manufacturers qualify for additional development assistance.

According to Mattia Binotto, a manufacturer with a genuine performance advantage, such as Mercedes, may have chosen not to reveal the full potential of its power unit.

It is no secret that the Mercedes engine has long been regarded as one of the strongest, if not the strongest, on the Formula 1 grid. For that reason, many expected the Silver Arrows’ power unit to top the FIA’s rankings.

Instead, the FIA’s data, which evaluates only the internal combustion engine as agreed by the manufacturers, painted a very different picture. The Federation’s analysis identified the Red Bull V6 as the most powerful engine on the grid. While nobody questions the outstanding work carried out by the engineers in Milton Keynes, the FIA’s conclusions came as a genuine surprise.

Even more unexpectedly, the figures suggested that Mercedes was more than two percent down on the Red Bull engine in terms of combustion engine power. That would make Mercedes eligible for ADUO concessions, allowing the manufacturer access to additional development resources and the opportunity to homologate an upgraded power unit. It is important to remember that the ADUO system evaluates only the internal combustion engine and does not take the MGU-K into account.

After reviewing the FIA’s findings, Red Bull requested that the Federation reassess the data, arguing that its own internal analysis indicated there was indeed a power difference—but one that favored Mercedes. The key issue is not necessarily identifying which manufacturer has the strongest engine, but rather determining which companies should benefit from the development concessions offered under the ADUO system. That is precisely why Red Bull challenged the FIA’s conclusions.

Behind the scenes, there has been growing speculation that one or more manufacturers may have deliberately concealed their true engine performance, whether for reliability reasons or to secure the additional development opportunities provided by ADUO. In an exclusive interview with Motorsport.com, Mattia Binotto did not question the FIA’s measurements, stressing that the governing body has all the necessary tools to carry out accurate assessments. However, he argued that the procedures themselves deserve to be reconsidered.

“I don’t question the work carried out by the FIA. They have all the tools and all the data necessary to perform their evaluations, even with the limitations that every measurement system inevitably has. However, I think it’s important to remember what the original purpose of ADUO was. At the beginning, when it was first discussed, the idea was to create a kind of safety net,” explained the Audi Team Principal. Audi was the first manufacturer to take advantage of ADUO by introducing an upgraded engine at the Spanish Grand Prix, the race immediately after the FIA published its engine rankings.

“That’s where the concept of performance convergence came from: to allow those who had fallen behind to have a better chance of catching up. It’s the same principle that already exists for the chassis and aerodynamics. Teams lower in the championship receive more wind tunnel time. In the same way, manufacturers that are behind in terms of power unit performance receive greater development opportunities so they can close the gap and make the championship more competitive.”

According to Mattia Binotto, the fundamental weakness of the current system is that ADUO values are determined exclusively from data collected on track, creating the possibility of discrepancies. Even before the season began, the Audi Team Principal had warned that manufacturers could manipulate the power output of their engines, and he now believes that scenario may well have unfolded during the opening part of the championship.

As FIA Single-Seater Director Nikolas Tombazis explained during the enforced break before the Miami Grand Prix, the Federation calculated ADUO values by analysing data gathered from the fastest-performing car of each manufacturer before filtering the information according to the specific context. For example, on long straights, engineers measured engine output at the beginning of the acceleration phase rather than at the end, where aerodynamic differences between the cars have a much greater influence and could distort the results.

Using those measurements and a statistical model, the FIA calculated the performance values of every Formula 1 power unit. However, Mattia Binotto believes this methodology may have left the door open for manufacturers—particularly one with a significant performance advantage, such as Mercedes—to reduce engine output without revealing their true capabilities. This would have been especially relevant during the first evaluation period, which ran until the Canadian Grand Prix, when Mercedes arguably enjoyed a clear advantage over its rivals.

“In my opinion, the biggest limitation was measuring only the performance shown on track. A car that already has an overall performance advantage can afford not to use the full potential of its power unit. It’s possible, for example, that Mercedes had an engine capable of producing more power but had no need to run it at its limit because the car already enjoyed an advantage. If that were the case, it could also have secured additional development opportunities,” explained Binotto.

“That’s why I believe the regulations should be reconsidered in this area. The original purpose of ADUO was not this. The goal was to help those who had genuinely fallen behind, not to create situations where the true potential of a power unit becomes difficult to assess.”

The FIA had originally planned to include additional factors when defining the ADUO system, taking into account secondary parameters such as turbocharger dimensions. Last spring, the Federation presented manufacturers with a more sophisticated evaluation model. However, after the teams rejected the proposal, the FIA retained the existing methodology, leaving the current engine assessment criteria unchanged.