ADUO: Tombazis explains evaluation parameters and a decision made by the teams

FIA Single-Seater Director Nikolas Tombazis held a press briefing today with selected media, including ScuderiaFans.com, to discuss the regulatory changes that — pending World Motor Sport Council approval this week — will be introduced starting from Miami.

The meeting also provided an opportunity to address other key topics, including the ADUO system and the engine concessions that could have a significant impact on the rest of the Formula 1 season.

How will ADUO be defined? Teams opted for a less complex system

One of the major talking points after Formula 1 resumes will undoubtedly be the ADUO system and the concessions granted to engine manufacturers, which could play a decisive role in shaping the remainder of the championship.

“We still have one month before the first batch of results: so Miami and Canada are still to come,” Nikolas Tombazis clarified.

Two more Grands Prix will therefore be used for data collection before finalising the results and producing a ranking that will identify not only the best engine, but also the performance gaps between manufacturers and who will be eligible to benefit from the ADUO system.

AutoRacer has already conducted analysis suggesting that, in terms of ICE power output, Mercedes is currently the benchmark, with Red Bull very close behind. Ferrari, Audi, and Honda would instead fall within the concession zone, with gaps exceeding 4%.

Official confirmation is still required, but Nikolas Tombazis has already explained how the FIA will analyse the data collected on track.

The decision was not taken by the governing body alone, as the teams were also involved in defining the parameters used in the ADUO evaluation.

“Internal combustion engine performance is influenced by important but secondary parameters such as plenum temperature, turbo temperature, or exhaust pressure.”

This last point is particularly interesting, as paddock rumours — possibly indirectly referenced here — suggest that Ferrari’s SF-26 FTM system may influence exhaust behaviour and engine operating temperatures, potentially resulting in a loss of horsepower from the power unit. Could this affect ADUO evaluation?

Tombazis explains why the answer is no:

“About a year ago we gave manufacturers the option of a slightly more complex formula, where these factors would be taken into account, but they were quite categorical in wanting to exclude them. So we are without corrections of that nature, and the regulation only considers power where it actually matters.”

ADUO values will therefore be based purely on ICE performance, without external factors influencing the output.

How and when is engine power calculated?

“For each race we take the best-performing car from each manufacturer and analyse multiple laps in order to obtain an average.”

The FIA then focuses, Nikolas Tombazis explains, on key performance zones such as “the start of the straight, and not the end of the straight.”

The Greek engineer describes this as a reasonable methodology, “discussed and agreed with the teams. We also have significantly improved sensors, so we believe the measurements can be fairly accurate.”

Nikolas Tombazis’s explanation of the ADUO framework therefore highlights a move toward transparency and technical fairness in the 2026 engine era. By focusing on pure ICE output and excluding secondary variables at the teams’ own request, the FIA is aiming for a simplified yet accurate assessment of the power hierarchy. As the circus heads to Miami and Canada, the data gathered will be instrumental in deciding which manufacturers receive the help they need to bridge the gap to Mercedes, potentially reshuffling the competitive order for the second half of the 2026 Formula 1 season.