What is ADUO in F1?

ADUO stands for Additional Development and Upgrade Opportunities, a new mechanism baked into F1's 2026 power unit regulations, designed to stop one manufacturer from running away with a huge performance advantage the way Mercedes did after the last major engine overhaul in 2014, when the power unit determined the competitive order more than anything else. 

It gives the five power unit manufacturers a structured way to improve their engines mid-cycle if they're lagging behind the benchmark performer – a safety valve built into the rules so a trailing manufacturer has a defined path to catch up during the season, without the political fights that used to accompany mid-cycle engine rule changes. 

The FIA monitors each manufacturer's Internal Combustion Engine performance and builds an "ICE Performance Index" using factors like engine speed, input shaft torque, and MGU-K power output, weighted for how much power sensitivity affects lap time. This index looks only at the ICE – it isn't a full measure of total power unit performance, since the energy recovery system also plays a major role in overall output. 

Manufacturers within 2% of the leading engine are considered competitive and get no ADUO allowance, since closing that small a gap is treated as normal engineering work. Those 2-4% behind get one upgrade opportunity that season and one the following season; those 4% or more behind get two upgrades in the current season and two more the next. 

Financially, the allowances scale with the deficit: roughly $3 million for a 2-4% gap, up through $8 million for an 8-10% gap, and more beyond that. Crucially, this spending sits outside the normal $215 million team cost cap and separate manufacturer cost cap, since ADUO is fundamentally a cost-cap relief mechanism. 

ADUO only applies to the power unit (engine, turbocharger, energy recovery system, battery, control electronics_ not to the chassis or aerodynamics, so it can't be used to unlock extra wind-tunnel time or bodywork upgrades. Upgrades aren't cumulative within a single season – a manufacturer only receives the grant the first time it qualifies, though allowances can carry over and stack with new grants across seasons if a manufacturer keeps qualifying.