The term 'ADUO' is poised to dominate the Formula 1 paddock in 2026, and Sky Sports F1 delves into why the sport's new engine development rules have become a hotly debated topic. Following the most significant regulation change in F1 history, which introduced new power units alongside new chassis and increased electrical power to achieve a 50-50 split with internal combustion engines, the potential for performance gaps led to the inclusion of performance-balancing measures in the rules. Additional Development and Upgrade Opportunities, or ADUO, is a specific component of the F1 rules focused on power units, allowing the five manufacturers to enhance their models if they lag behind the top performer.
The benefits of ADUO are already apparent, as seen with Aston Martin, a team expected to be competitive but is struggling due to severe issues with their Honda power unit. Without ADUO, they might have been relegated to being backmarkers for the entire season, but the chance to upgrade their engine offers hope for improvement during the campaign. However, a dispute is emerging over whether other manufacturers, such as Ferrari, Red Bull, and Audi, should be allowed to narrow the performance gap with the Mercedes power unit, which has set the early benchmark.
Ferrari's boss, Fred Vasseur, views ADUO as an opportunity to 'close the gap' to Mercedes, whereas Toto Wolff, the Silver Arrows' chief, has urged the FIA to prevent engine upgrades from interfering with the competitive order. ADUO concentrates on the internal combustion engine (ICE) part of the power unit, with the FIA measuring power unit performance at every race using a performance index not available to the media. Manufacturers trailing the leading ICE by two per cent or more will be granted ADUO, with those between two and four per cent behind receiving one development opportunity and those four per cent or more behind getting two opportunities. The outcomes of the opening rounds, all won by the Mercedes works team, suggest their self-made engine will be the benchmark.
Speculation indicates that despite being off the pace overall, Red Bull's ICE performance might be strong, potentially not more than two per cent behind Mercedes. The FIA had planned to review ICE performance after the sixth, 12th, and 18th rounds, with those granted ADUO able to implement upgrades immediately for the seventh round. However, due to the cancellation of rounds in Bahrain and Saudi Arabia, the FIA is reassessing this timeline and may alter the percentage thresholds.
Manufacturers supplying multiple teams must ensure they can provide sufficient engines to implement upgrades. For instance, Ferrari, which supplies engines to Haas and Cadillac, must offer their customers the same ICE specification as their own to introduce the upgraded model.
This poses a greater challenge for Ferrari compared to a manufacturer like Audi, which only builds its own engines. The three weeks between the Miami Grand Prix and the Canadian Grand Prix would not be sufficient for a manufacturer to design and produce upgrades, as they would have been working on improvements since submitting their initial models for the season start. Vasseur's comments suggest all four of Mercedes' rival manufacturers anticipate being granted ADUO and likely have new elements ready for the Canadian Grand Prix.
Even Mercedes will be working on engine development, as all manufacturers can introduce upgrades for 2027 regardless of their standing. It's also possible for manufacturers to make upgrades to all power unit parts, including both ICE and electrical elements, if they can prove to the FIA that the changes are for reliability, safety, cost-saving, or supply issues. While Vasseur and other non-Mercedes engine teams see ADUO as a chance to make gains, Wolff appears unconvinced that any manufacturer other than Honda should significantly upgrade their engine. Wolff stated that the principle of ADUO was to allow teams on the back foot to catch up, not leapfrog, and emphasized the need for clarity, precision, and transparency in ADUO decisions to avoid impacting the championship.
Wolff also warned against gamesmanship, possibly referring to teams attempting to display lower ICE performance for a better ADUO outcome. As the season unfolds, ADUO is likely to remain a significant topic. Formula 1 resumes on May 1-3 with the Miami Grand Prix, the season's second Sprint weekend, live on Sky Sports F1.