The FIA have confirmed a key adjustment to Formula 1’s 2026 engine regulations, bringing forward an important development opportunity that could reduce Mercedes’ early advantage under the new power unit era.
The change centres around the Additional Development and Upgrade Opportunities system, known as ADUO, which was introduced to help manufacturers struggling with the all-new 2026 engine regulations. The mechanism gives underperforming power unit suppliers extra time and flexibility to improve reliability and performance during the season.
Originally, the first ADUO assessment period was scheduled to take place after round six of the championship. However, because the Bahrain and Saudi Arabian Grands Prix were cancelled amid the ongoing conflict in the Middle East, the 2026 calendar was shortened from 24 races to 22 and left without any events in April. As a result, the FIA has now revised the timing of the development windows.
The first ADUO period will now begin after round five at the Canadian Grand Prix later this month. The second window has been moved to after the Hungarian Grand Prix, now the 11th race of the season, while the final opportunity will remain after round 18 in Mexico.
The adjustment could prove significant for the competitive balance of the championship. Mercedes currently appear to have produced the strongest power unit on the grid, with both the factory team and its customer squads benefiting from impressive pace and reliability in the opening races of the new era.
By moving the ADUO process forward, rival manufacturers such as Ferrari, Red Bull Powertrains, Audi and Honda may gain access to upgrades sooner than expected, potentially allowing them to close the gap to Mercedes more quickly.
Under FIA regulations, manufacturers qualify for extra development support depending on how far their engines fall behind the benchmark power unit. If an internal combustion engine is between two and four per cent behind the best-performing engine, the manufacturer is allowed one additional homologation upgrade during both the 2026 and 2027 seasons.
If the performance deficit exceeds four per cent, teams can receive two extra upgrades in each of the next two years. The amount of development time also increases depending on the scale of the disadvantage. Manufacturers slightly behind the leaders receive 70 operating hours, while those more than 10 per cent adrift could gain as many as 230 hours to work on improvements.
With Mercedes currently leading the way, the accelerated ADUO schedule may give their rivals a valuable chance to fight back sooner than anticipated.