The FIA has sent a decree to all Formula 1 teams regarding the first assessment period under the Additional Development and Upgrade Opportunities (ADUO) system, which is set to change everything for the 2026 season. Contrary to expectations, Mercedes is not at the top of the list.
Assessment Results Surprise the Paddock
The results of the FIA's assessment are not good news for Red Bull or Ferrari. Red Bull and Ferrari have suffered a setback to their engine development ambitions as the FIA delivered its verdict to Formula 1 teams following the initial assessment phase. Under the newly-implemented ADUO framework, manufacturers trailing significantly in performance can secure eligibility to enhance their power units.
The widespread belief throughout the paddock was that Mercedes held the advantage, considering their commanding early-season form this year. Yet a communication distributed to all of F1's engine suppliers at the Monaco Grand Prix on Sunday by the FIA revealed an unexpected conclusion.
Following examination of each manufacturer's internal combustion engine (ICE), excluding the battery pack, the FIA has determined the Red Bull power unit to be the standard-bearer. Mercedes possess the second strongest engine and qualify for one development opportunity for being more than two per cent behind, while Ferrari, Audi and Honda are all four per cent or more off the pace.
The announcement left numerous individuals throughout the paddock baffled. And it appears poised to have a substantial influence at the front of the grid regarding the balance of power between the likes of Mercedes, Ferrari and Red Bull going forward.
Pride and Punishment for Red Bull
For Red Bull, there will be internal satisfaction that their maiden attempt at an F1 combustion engine has been deemed the finest on the grid. Red Bull Powertrains was constructed from the ground up for this regulations era and the choice to recruit some of the sharpest talents from established F1 engine manufacturers like Mercedes and Ferrari has proved worthwhile.
But for their competitive aspirations this season, it represents a setback. They now understand that they will be unable to implement any modifications to their power units. And there will be no additional testing allocation and cost cap budget available to RBPT, while those who do meet the criteria for upgrades will receive an extra provision on those matters.
Red Bull had anticipated securing the opportunity to upgrade their engines. Team principal and chief executive Laurent Mekies recently informed reporters: "What we see is certainly Mercedes, a long way ahead of most of us." He refused to comment on the ADUO conclusions following Sunday's race.
Also, confirmation that Red Bull possess the most powerful combustion engine on the grid will undoubtedly place a sharper spotlight on the departments in which they are deficient. The majority of Max Verstappen's grievances have concerned a shortage of aerodynamic balance in the machine and further questions may now potentially be directed towards technical director Pierre Wache.
Ferrari's Task Has Been Complicated
It had always been anticipated that Ferrari would have the capacity to enhance their power units. And there was positive news for the Scuderia as, due to their ICEs being assessed as more than four per cent behind the Red Bull engines, they will be permitted to homologate two upgrades this season and will also enjoy an increased cost cap alongside additional bench testing hours.
Their challenge, however, has been made somewhat trickier by the realisation that Mercedes are not the benchmark after all. With the Silver Arrows now also granted permission to develop their power units further, the fixed target that Ferrari believed they would have has now disappeared.
If Mercedes were the benchmark then any enhancements made to Ferrari's own ICEs would have drawn them closer on power to the team presently dominating the grid. But now, Mercedes have an opportunity of their own to counterbalance any prospective Ferrari advances.
In any event, Lewis Hamilton acknowledged himself following the Monaco race that this will not represent an overnight improvement for his team. He said: "We've now got these tokens to try to develop and close the gap, but that's like an eight-to-10-month project, so it's not something we can just do next week. We'll be pushing as hard as we can to see how we can close it out."
What It Implies About Mercedes
As for Mercedes, the implication of the FIA's findings is that they are extracting considerably more from the electrical components of their power units, which fell outside the scope of the ADUO assessment process. The evidence speaks for itself — they are the team that has claimed victory in every Grand Prix so far this season.
The sole occasion they have been bested in any race format in 2026 was when Lando Norris triumphed at the Miami Sprint. He achieved that, naturally, behind the wheel of a McLaren fitted with a Mercedes engine. They struggled for pace in Monaco, yet demonstrated during that Miami weekend in particular that they have made considerable strides in understanding the 2026 Mercedes power unit and unlocking its full potential.
As Hamilton pointed out, any manufacturer granted permission to introduce an upgrade will not be in a position to deploy it straight away. But when Mercedes do eventually homologate their engines once more, it could have a knock-on effect for their power unit customers, who will find themselves having to get to grips all over again with how the updated specification performs.
