The Fédération Internationale de l'Automobile (FIA) has officially confirmed that Mercedes will be permitted to introduce upgrades to its power unit, even though rival teams, most notably Red Bull, have voiced strong objections. This decision is part of the Additional Development and Upgrade Opportunities (ADUO) framework that the governing body introduced alongside the rollout of brand‑new engines for the 2026 Formula 1 season. ADUO was designed to give manufacturers a structured pathway to close any performance gaps that may emerge during the multi‑year engine regulation cycle, ensuring that no single power unit can dominate the sport unchecked.
In June, after the first performance review covering the opening five rounds of the championship, the FIA announced that Red Bull’s power unit had been judged the strongest of the field. Consequently, the regulator granted additional homologation slots to Mercedes, Ferrari, Audi and Honda, allowing each of those manufacturers to develop and install extra upgrades in the 2026 and 2027 seasons. While the FIA did not release a formal press brief at the time, the outcome was confirmed by team principals and drivers, and a leaked internal document later corroborated the findings. The decision sparked controversy across the paddock.
Mercedes, whose works team had secured victories in the first six Grands Prix, was seen as receiving a benefit that could widen its advantage, whereas Red Bull – which had managed only a single podium finish in the same period – appeared to be penalised despite its engine being classified as the benchmark. The perception that the reigning champions were being handed extra development leeway while the perceived under‑performer was left to fend for itself raised questions about fairness and the transparency of the ADUO process.
Red Bull’s lead driver, Max Verstappen, publicly criticised the ruling, suggesting that the assessment methodology was flawed. Meanwhile, Mercedes team principal Toto Wolff, who in July asserted that his squad possessed "the most powerful power unit," demanded greater clarity on the criteria used by the FIA to allocate these upgrades. The governing body initially refrained from confirming the details while it conducted a second review period, which concluded after the Hungarian Grand Prix, just before the summer hiatus.
When the FIA finally released its findings for both review windows, it confirmed the earlier leaks and added new information. For the first period, the statement read: "Mercedes were determined to be within the two‑to‑four‑percent performance window and will therefore be allowed one additional homologation in 2026 and one in 2027, together with corresponding increases to the cost cap and dyno testing allowances.
Audi, Ferrari and Honda were determined to be above the four‑percent threshold and will each receive two additional homologations in 2026 and two in 2027, also with appropriate cost‑cap and testing adjustments." The second‑period assessment delivered a further setback for Red Bull. The FIA announced that no additional homologations would be granted to any power‑unit manufacturer for the upcoming cycle.
This implies that Red Bull’s engine is now considered to be operating within two percent of the best unit on the grid, effectively confirming its status as the leading power unit, or at least very close to it. Had any of the other manufacturers improved sufficiently since June to surpass Red Bull, the British team would have qualified for its own upgrade slot, but the data showed otherwise. In the drivers' championship, Mercedes’ Kimi Antonelli (a fictional placeholder for illustrative purposes) leads his teammate George Russell and Ferrari’s Lewis Hamilton by 59 points, while Verstappen trails the Italian by 130 points, sitting in sixth place.
In the constructors' battle, Mercedes enjoys an 87‑point lead over Ferrari, with third‑placed McLaren – which also runs a Mercedes engine – enjoying a resurgence thanks to Lando Norris’s recent back‑to‑back victories. Since the June announcement, Mercedes has been free to apply its 2026 upgrade, though the team has not yet revealed whether it has done so. Ferrari, Audi and Honda are each believed to have introduced one of their two allotted upgrades for the upcoming season.
The FIA’s director of single‑seater competition, Nikolas Tombazis, emphasized the rigor of the ADUO review, stating that the analysis was "thorough and exhaustive" and that the organization has a high degree of confidence in its conclusions. He also highlighted the need to protect the confidentiality and intellectual property of the teams, noting that the ADUO system is in its inaugural year and will likely evolve through ongoing dialogue with power‑unit manufacturers.
The third ADUO review window began at the Dutch Grand Prix and will run through the Mexico City Grand Prix on November 1, giving teams another opportunity to demonstrate performance gains and potentially earn further upgrade allowances before the season concludes. As the championship heads toward its final races, the stakes are high for both the manufacturers seeking to maximise their development budgets and the teams hoping to translate technical advantage into podium finishes. Looking ahead, Formula 1 will travel to Monza for Ferrari’s home Grand Prix on September 4‑6, an event that will be broadcast live on Sky Sports F1. Fans can stream the coverage via NOW, with no long‑term contract required, and can also tune into The F1 Show podcast for in‑depth analysis of the ongoing ADUO saga and its implications for the title fight.
The evolving landscape of engine development, regulatory oversight, and competitive balance continues to shape the sport, ensuring that the battle on the track is matched by a complex strategic contest behind the scenes.