The FIA will not to offer any engine manufacturers the chance to perform extra power unit upgrades following its latest Additional Development and Upgrade Opportunities (ADUO) evaluation.

Under new rules introduced as part of Formula 1’s 2026 power unit regulations the sport’s governing body controls how often manufacturers can upgrade their internal combustion engines.

The evaluations take place periodically throughout the season. The FIA has completed its third such evaluation and, as was the case during the second, determined no further engine homologation opportunities should be offered.

The third evaluation period concluded after the United States Grand Prix last month. The second followed the Hungarian Grand Prix.

The first evaluation period, which ran from the start of the season to the Canadian Grand Prix, remains the only time any additional upgrade opportunities were awarded. On that occasion Red Bull-Ford were found to have the top-performing power unit.

Audi, Ferrari and Honda’s units were found to be more than 4% less powerful. They were permitted two extra homologation opportunities this year and two more next year. Mercedes were found to be within 2% and 4% of the leading power unit and therefore received one extra upgrade this year and next.

Separately, in May the FIA changed the ADUO rules to allow any manufacturer which was 10% off the leading design to spend more money. The revision was expected to assist Honda following their poor start to the season.

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Some have likened F1’s ADUO to the World Endurance Championship’s heavily-criticised Balance of Performance regulations. The FIA’s single-seater director Nikolas Tombazis defended the regulations but indicated they may be revised in coming seasons.

“Based on the quality of the data and the robustness of the assessment process, we are confident in our findings and the conclusions reached,” he said.

“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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