Red Bull has been declared Formula 1's best engine under the Additional Development and Upgrade Opportunities (ADUO) system, The Race understands, meaning Mercedes and Ferrari will both get engine upgrades during the 2026 season.

The Race has learned that teams were informed on Monaco Grand Prix race day of the FIA's first judgement of the engine pecking order and who will be allowed opportunities to try to gain ground.

Under the upgrades system, if a manufacturer is deemed to have a power unit that is more than 2% adrift of the benchmark at a certain point - with the first of three such points in 2026 coming after the recent Canadian GP - then it will be allowed to make one upgrade for 2026 and another for 2027.

If the deficit is 4% or more, then the manufacturer will be allowed to make two upgrades this season and two more the following campaign.

Although Mercedes has been regarded as the benchmark power unit and is dominating the championship, the Ford-branded Red Bull Powertrains engine has actually been classified as the best under the criteria used for ADUO.

The exact metrics of how that is done are not clear as these are not laid out in the regulations, as the FIA was wary of teams trying to game the system if it laid out some clear measurement metrics for what its analysis and decisions would be based on. It suspected some manufacturers would try to engineer power units that would score low in these areas to help it look like they were behind and so qualify for upgrades.

Only one power unit element came into play: the internal combustion engine.

Any advantage a team has from better energy harvesting, deployment, efficiency, or more advanced management of energy (which includes control of the MGU-K or better battery technology) is totally outside the remit of what falls under the qualifying criteria for additional development opportunities.

The Red Bull engine has been ruled the best right now under the FIA's criteria so it does not qualify for ADUO.

Mercedes gets one upgrade homologation because it has been judged as more than 2% adrift, while the other manufacturers - including Ferrari - get two homologations because they have been declared over 4% adrift.

Because two is the maximum that can be offered right now, the ADUO ruling does not imply that Ferrari and Honda are at the same level, just that both are somewhere over 4% off Red Bull under the rules used.