FIA confirms findings after final F1 2026 ADUO window closes
Kimi Antonelli (Mercedes W17) leads at the start of the 2026 Brazilian Grand Prix
The FIA had confirmed that no further upgrades have been granted to F1 2026 engine manufacturers after the latest ADUO window closed.
The Additional Upgrade and Opportunities scheme was introduced by Formula 1’s governing body ahead of the F1 2026 season to help struggling manufacturers catch up.
FIA confirms latest ADUO findings after final F1 2026 window shuts
The ADUO system sees the power of each manufacturer’s internal combustion engine measured across regular intervals throughout the season.
The first review period ended following the Canadian Grand Prix in May, with the second shutting after the Hungarian Grand Prix in July.
Any manufacturers found to be two per cent weaker than the best-performing ICE have been granted additional upgrades to help close the deficit.
Following last weekend’s Brazilian Grand Prix, the FIA has confirmed the results from the third and final ADUO window of the F1 2026 season, which fell between August’s Dutch Grand Prix and last month’s United States Grand Prix.
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In a statement issued to PlanetF1.com, the FIA said that the third assessment “did not result in any additional homologations being granted to the power unit manufacturers” despite “the relative gaps to the leading ICE” evolving since the second window closed.
The governing body added that the results of the latest ADUO analysis period have been communicated to all power unit manufacturers, with the FIA declining to offer further details on power unit performance index measurements “due to the confidential nature of this information.”
The next ADUO review window will begin at the start of the F1 2027 season in Bahrain and cover the opening six races of the campaign.
The FIA’s latest update means the number of upgrades granted to manufacturers remains unchanged from the first ADUO analysis window, after which Red Bull Powertrains was found to have the strongest internal combustion engine of 2026.
The decision meant Mercedes, whose ICE was judged to be between two and four per cent weaker than Red Bull’s, was permitted one additional upgrade for 2026 and a further one for 2027.
Audi, Ferrari and Honda were found to be in excess of four per cent down on Red Bull, with each manufacturer granted two additional upgrades for 2026 and two for 2027.
The additional upgrades granted under ADUO also came with increased leeway with the cost cap and engine dyno testing.
Nikolas Tombazis, the FIA’s single-seater director, said: “The FIA has undertaken extensive analysis as part of the review of ADUO this year.
“Based on the quality of the data and the robustness of the assessment process, we are confident in our findings and the conclusions reached.
“The first year of implementation has also reinforced our belief that the ADUO concept is the right one for Formula 1.
“However, it is important that the system continues to evolve to ensure it remains efficient, relevant and fit for purpose.
“To that end, 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.”
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