Formula 1's biggest talking point coming out of Monaco was not Kimi Antonelli's fifth straight win. It was a single page that landed in team motorhomes on Sunday and quietly bent the 2026 title picture out of shape.
That page was the result of the FIA's first ADUO assessment of the season. ADUO — Additional Development and Upgrade Opportunities — is the catch-up mechanism written into the 2026 rules. Engines are frozen, but if a manufacturer's internal combustion engine falls more than two percent behind the benchmark, one development slot opens up; more than four percent back, and a second slot unlocks. Crucially, the slots come with cost-cap relief, so the work can be funded outside the normal budget limit.
The shock was who the benchmark turned out to be. According to The Race, the document names Red Bull Ford Powertrains as the best internal combustion engine on the grid — not Mercedes, who have won every race this season. "Red Bull powertrains is the benchmark engine. Mercedes is second best, it's at least two percent behind, and Ferrari, Audi and Honda are further adrift," The Race's John Noble laid out, with the official version due to be published Monday.
The numbers that have leaked tell the story. Mercedes sit roughly 12 to 24 horsepower behind on the combustion side and qualify for a single upgrade token. Ferrari, judged to be four to six percent down, get two slots and hold more development tokens than anyone on the grid. Audi take two as well, while Honda — last in this particular ranking — fall into a six-to-eight percent band that frees up still more budget and time.
The irony was not lost on anyone. The team that built the best engine cannot touch it, while the team winning every Sunday gets handed a token. The Race put it with a dry edge: building an F1 engine for the first time, it turns out, is easy after all, because Red Bull have done exactly that and gone straight to the top. The Hot Lap was more generous, calling it a stunning job by Red Bull Powertrains and Christian Horner's recruitment drive, while noting Mercedes remain "the best overall package by none" and may simply be sandbagging the combustion figures.
That tension drove the loudest disagreement. LawVS argued the whole exercise misses its own point: Mercedes plainly do not need an extra dozen horsepower — Antonelli and George Russell were winning in Australia without it — and a rule stamped as fairness could end up being gamed by the teams it was meant to rein in. "Who was this rule designed for, and who wrote this rule?" he asked. Aidan Millward took the longer view, giving the FIA credit for trying to narrow the field and drawing the parallel with the old token system that left a struggling Honda spending upgrades just to stand still in 2015.
The driver voice that mattered came from Lewis Hamilton. Speaking to Sky Sports F1, he confirmed the assessment had been communicated to the teams and laid out the order without softening it: Red Bull hold the most powerful engine, Mercedes are second, and Ferrari are running behind both. The tokens, he said, give Ferrari the right to develop — but he attached a sobering timeline of eight to ten months, not something his team can solve in the coming weeks.
One detail keeps the verdict in perspective. ADUO covers only the V6 combustion engine, not the energy-recovery side, where Mercedes' real advantage may live. The official document goes public on Monday. Barcelona, the first true high-speed test of these cars, will start to show whether any of it matters.
---