The ADUO-upgraded Ferrari power unit that debuted at Monza will also go into Sergio Perez's Cadillac in Baku this week. His team-mate Valtteri Bottas and Haas's Esteban Ocon remain on the previous specification for now. The unit is designed to cut Ferrari's straight-line deficit to the Mercedes HPP engine, which means Cadillac, still pointless this season, arrives at the circuit with F1's longest straight carrying the very part it has missed most.
What is ADUO?
ADUO stands for Additional Development and Upgrade Opportunities. According to F1.com's explainer, it is a mechanism introduced for the 2026–2030 power unit regulation cycle that grants any manufacturer whose internal combustion engine (ICE) performance index trails the leading engine by 2% or more extra homologated upgrades, budget cap headroom and additional dyno time. A deficit of 2–4% earns one extra upgrade this year and one next year; 4% or more earns two in each. The budget allowance ranges from $3 million per review period (2–4%) to $11 million (10% or more). The FIA stresses that this is budget cap relief, not a performance balancing tool. The index is calculated from engine speed, input shaft torque, MGU-K output and lap-time sensitivity, and because it looks only at the ICE, F1.com adds, it is not the same as overall power unit performance.
In the results of the first review period (up to the Canadian GP), published by the FIA on 26 August, Ferrari was placed in the band above 4% alongside Audi and Honda, earning two extra homologations in 2026 and two in 2027. Mercedes fell in the 2–4% band, with one in each year. No further manufacturer qualified in the second review period, which ran to the Hungarian GP.
What the Monza spec changed
According to RacingNews365, Lewis Hamilton, Charles Leclerc and Haas's Oliver Bearman were the first to run the upgrade at the Italian GP, while Ocon and both Cadillacs could have taken it but have not yet done so. The aim is to "erase some of the straight-line speed deficit to the Mercedes HPP design". In its pre-Monza report, Motorsport.com called the unit the second ADUO upgrade (ADUO2), built around combustion chamber improvements, a revised turbocharger, a new Shell fuel and changes to torque delivery for electrical energy deployment, targeting around 15hp to halve the gap to Mercedes. It added that the unit was cleared for racing after passing reliability thresholds in repeated bench testing.
Why Perez gets it in Baku
According to GrandPrix247, Cadillac will fit the new-spec Ferrari power unit to Perez's car this week, with Bottas continuing on the existing hardware. The team is also bringing a small aerodynamic upgrade to evaluate in practice. Paddock News 24 wrote that the unit is the same specification Hamilton and Leclerc used at Monza. Team principal Marcin Budkowski said: "As we continue to develop this year's car, we have a small aero upgrade to test in free practice." In a separate interview with RacingNews365, he pointed to energy management as Cadillac's weakness, despite using the same unit as Ferrari.
Cadillac has yet to score after 14 rounds, with Bottas's 13th place in China its best result. Perez crossed the line 10th in Monaco but lost the point to a post-race penalty. Perez himself reflected that "the Madrid race was going really well until the retirement, and it was probably our strongest of the season." In Baku he has stood on the podium five times: wins in 2021 and 2023, second in 2022, and third in 2016 and 2018. Bottas said the circuit "has the longest straight in F1, but the rest of the lap is very technical too." On a track where the long straight lays bare every step of power unit performance, Perez is chasing Cadillac's first point.
Sources
- GrandPrix247 — Cadillac bring upgrades and new Ferrari Formula 1 power unit to Baku
- RacingNews365 — Sergio Perez armed with fresh Cadillac weapon in Baku happy hunting ground
- RacingNews365 — Why Sergio Perez offers Cadillac a rare shot to break F1 points duck in Baku
- Paddock News 24 — Sergio Pérez eager for Baku, his perfect hunting ground
- Formula1.com — EXPLAINED: What is F1's 'ADUO' engine upgrade system and how will it work
- FIA — FIA announces ADUO results following first and second review periods of 2026
- Motorsport.com — Ferrari to deliver upgraded F1 engine at Italian GP