Mattia Binotto concerned Formula 1 power unit manufacturers can exploit the ADUO

The ADUO was introduced in 2026 along with the new regulations to make sure that no manufacturer falls behind in case they start with a power deficit.

That was kept in mind with Audi joining the sport, with Cadillac also coming in but with their power unit coming in 2029.

A periodic evaluation (three review windows) of power units is done over the season with one upgrade given per 2% of power deficit a given manufacturer may have compared to the benchmark, and that is based on an evaluation of the Internal Combustion Engine (ICE).

The latest evaluation conducted by the FIA found that Red Bull Ford is the best ICE on the grid, while Mercedes are believed to have the best overall power unit considering the hybrid component, which is why Red Bull unsuccessfully contested the governing body's evaluation.

Thus, Mercedes were given an upgrade, which is basically allowing them to spend more money to develop their power unit. Ferrari, Audi, and the struggling Honda have been granted two upgrades as they were found to be 4% behind Red Bull Ford.

What makes matter more interesting is that, while the evaluation is based on the ICE, the upgrades are allowed to cover the whole power unit, even the electric component.

With performance on track being the means by which ADUO evaluation is done, there is a chance that a manufacturer with an overall chassis and hybrid advantage will turn down the ICE.

That is the case Binotto pointed out while claiming the ADUO system needs to be reviewed.

He told Motorsport.com: "In my opinion, the limit has been that it has exclusively measured performance on the track. A car with an overall advantage can afford not to fully exploit the potential of its power unit.

"It's possible, for example, that Mercedes had an engine with superior potential but had no need to push it to the limit because it already had an advantage thanks to the car. If that were the case, it could have also gained additional development margin.

"That's why I think the regulation needs to be rethought in this regard. This wasn't the original intent of the ADUO: the goal was to help those who were actually falling behind, not to create situations in which the true potential of a power unit might be difficult to assess," Binotto explained.

And while he had issues with the ADUO system, Binotto absolved the FIA of any wrongdoing in their evaluation. He added: "On the results, I'm not questioning the work done by the FIA.

"They have all the tools and data necessary to make their assessments, despite the limitations that any measurement system inevitably entails.

"However, I believe it's important to remember the original objective of the ADUO. When it was first discussed, the concept was that of a sort of safety net.

"If a manufacturer was far behind at the start of the regulatory cycle, with regulations virtually frozen and very little room for development, it would risk dragging that disadvantage for five years.

"This gave rise to the concept of performance convergence: allowing those who were further behind to have a greater chance of catching up. Ultimately, it's the same principle that already exists for chassis and aerodynamics.

"Those further back in the standings have more hours in the wind tunnel. Likewise, those who are further behind in terms of power unit performance receive greater development opportunities to catch up with the others and make the championship increasingly balanced," the former Ferrari boss concluded.

In return, the FIA has argued that Formula 1 teams have agreed on the ADUO system as it is right now, in terms of restricting the evaluation to the ICE.