No More Engine Upgrades as the FIA Closes the Last ADUO Window of 2026

The FIA finished its last engine check of 2026, and nothing changed for the manufacturers. The results of the third ADUO period came out on Tuesday, November 10, in an FIA statement. It covered races 12 to 18, from the Dutch Grand Prix in August to the United States Grand Prix in October. “For the third period, the relative performance gaps to the leading ICE evolved, but these changes did not result in any additional homologations being granted to the Power Unit Manufacturers,” the FIA said. All five engine makers got the results.

ADUO stands for Additional Development and Upgrade Opportunities. It is a new part of the rules this year, and it looks at the combustion engine only. A manufacturer that is at least 2% behind the best engine gets extra homologations, so it can bring upgrades that are normally not allowed. It also gets more money under the cost cap and more hours on the dyno. If the gap is more than 4%, the help is bigger.

The big decisions came after the first period, which ended with the Canadian Grand Prix. The Red Bull Ford engine was the best one. Mercedes was between 2 and 4% behind, so it got one extra homologation for 2026 and one for 2027. Audi, Ferrari and Honda were more than 4% behind, and each of them got two for this year and two for next year. Red Bull Ford did not agree that its engine was the strongest, and it asked for a review. Because of this, the first results came out later than planned. The second period ended after Hungary, and it brought no changes either.

How big the gaps are now, we will not find out. The FIA said that “no further details on power unit performance index measurements will be communicated.”

Mercedes has both titles this year. Kimi Antonelli won the drivers’ crown in Mexico City, and a week later the team clinched the constructors’ one in Brazil. Still, the best combustion engine belongs to Red Bull Ford, according to the FIA, and Mercedes is behind it. Red Bull does not believe this at all. “It’s a shame that we’re losing so much on the straight,” Max Verstappen said at Monza. “That’s not news, we’ve known that for a while. Apparently we do have the fastest engine.” Team boss Laurent Mekies said that there is “not a single data point” that shows it. The reason is that ADUO counts only the combustion engine, without the battery and the energy use.

Nikolas Tombazis, the FIA director of single seaters, stands behind the results. “The FIA has undertaken extensive analysis as part of the review of ADUO this year,” he said. “Based on the quality of the data and the robustness of the assessment process, we are confident in our findings and the conclusions reached.”

But he also hinted that the system will change. “We have been working closely with the Power Unit Manufacturers and teams to explore refinements to the methodology that will support the continued effectiveness of ADUO in future seasons,” Tombazis said. This is not new from him. In August he already said: “This is the first year of ADUO so naturally there are areas which we may evolve over time, in discussion with all the PU Manufacturers.” The Race writes that one idea is to measure the whole power unit and not only the combustion engine. Another idea is to count things like turbo size and engine temperatures too. Mattia Binotto from Audi has his own idea. He would give the upgrades based on where a team finishes in the constructors’ championship.

Not every manufacturer has used its upgrades yet. Ferrari and Honda already brought their two for 2026, but Mercedes has not used its 2026 homologation so far. Audi plans its next step for 2027. An upgrade that is not used this year does not move to next year. The first period of 2027 will cover races 1 to 6, from Bahrain to Miami.

For the last three races in Las Vegas, Qatar and Abu Dhabi, ADUO brings nothing new. Mercedes still has its one upgrade for this year, and it can bring it in one of these three races.