Formula 1 has always been a sport of buzzwords and phrases that sound completely made up -- this year is no different, and the acronym ADUO is a buzzword fans will hear plenty of in the lead-up to and in the weeks after the Monaco Grand Prix.
So what’s the fuss about? Well, it could turn out to be a very significant acronym indeed, one which could significantly alter the competitive balance of the season. It is equally noteworthy as Ferrari has spent much of the season so far actively lobbying that it deserves to be given the extra engine upgrade opportunities which potentially come via ADUO.
But hold up ... apologies, we’re getting ahead of ourselves already. You still might not be sure what that even means.
Here’s everything you need to know about something which might well define how the rest of the F1 season shakes out.
What is ADUO?
The abbreviation stands for Additional Development and Upgrade Opportunities, a mechanism baked into this year’s regulations to give F1 and the FIA leeway to balance out the competitive order under the new rule set introduced this season.
It creates the potential for any of the five manufacturers to improve their engines mid-season -- crucially, outside of the usual restraints imposed on them by the cost cap -- should they be lagging behind the benchmark performer by a certain amount of time at different points in the season.
The FIA gave itself three windows in the season to measure the five manufacturers’ engines and to act accordingly -- originally the sixth, 12th and 18th of the 24 scheduled rounds.
The FIA revised the timeline after rounds four and five in Bahrain and Saudi Arabia were cancelled because of conflict in the Middle East, meaning the three new windows are after the new fifth race (Canada), 11th round (Hungary) and 18th round (Mexico). Canada has come and gone, meaning that the first window for measurement has expired.
Why does ADUO exist?
Ahead of the 2026 season, the sport was worried the new engines might create a massively spread out competitive field, or a situation where one (or more) manufacturers found themselves way off the pace of the lead engine.
When that was the case a decade ago, Honda joined the V6 turbo era a year late in 2015 and spent years painfully off the pace of Mercedes and others. Fears of similar happening again this time around were heightened with Audi joining, with the new regulation set being largely catered around the idea of bringing new manufacturers into the sport this season, thanks to the road relevance of the new V6 hybrid turbos.
Ironically, Mercedes is once again the lead benchmark, and Honda is once again painfully off the pace -- Aston Martin’s embarrassing start has almost been to demonstrate that a catch-up mechanism was needed in the first place.
There’s no debate around whether Honda qualifies for ADUO. What has made it noteworthy in the paddock is whether any of the other manufacturers chasing Mercedes -- Ferrari, Red Bull and Audi -- will get the benefits potentially afforded to them by the rule.
How is ADUO measured?
The governing FIA is using ADUO as a means of evaluating and ranking the outright performance of each internal combustion engine (ICE) on the grid. While much has been made of the 50-50 split between combustion and electrical power this year and the emphasis on battery harvesting, the ICE is still where the grunt and performance of an engine truly lies.
The ADUO system takes engine speeds, torque and other metrics into consideration to form a performance metric. It’s a highly complicated process, which includes a weighting to account for power sensitivity on lap time across measured laps.
The benchmark will be Mercedes’ class-leading combustion engine -- the rest will then be ranked in accordance with the specific thresholds the FIA has been working to in an ‘ICE Performance Index.’
Under the rules, the FIA had 14 days after the Canadian Grand Prix to release the rankings of that very index, meaning it will be public before the race in Monaco on May 7. Should any manufacturer drop below certain thresholds in that Performance Index, it will be granted extra development leeway not otherwise afforded to it under the current cost cap.
ADUO will be granted to any manufacturer that is deemed to be off the lead ICE by 2% points or more. This is where the measurements will be key: Manufacturers trailing by between 2 - 4% will be given one opportunity to develop their power unit this season, and one more in 2027; those trailing by 4% or more will get two opportunities in 2026 and two further opportunities in 2027.
Ordinarily, sweeping engine upgrades would be difficult within the cost cap, but any manufacturer granted ADUO will have leeway to operate outside of that. Any manufacturer between 2 - 4% off the benchmark will get an extra allowance up to $3 million; any between 4 - 6% will get an extra allowance of $6.35 million; any between 8 - 10% will get an extra allowance of $8 million, while any manufacturer judged to be 10% or more off the benchmark will get an extra allowance of $11 million.
Those are not insignificant numbers at all in the modern world of F1. Currently, teams operate within a $235 million cost cap every year, while the five manufacturers operate under a separate cost cap of $130 million for the season.
So Honda has a shoo-in -- could Ferrari really get it too?
Here’s where this all gets complicated and, in classic Formula 1 style, a little political. It’s been obvious since the beginning of the year that Honda would benefit from ADUO -- and it will be interesting to see just how far off the Mercedes engine the Performance Index judges them to be.
It might well give Fernando Alonso, Adrian Newey and Aston Martin hope of somehow turning around its dire situation in the longer term. Sources have told ESPN that Honda is expecting to get the full whack of extra upgrade potential afforded to them.
Beyond Honda, it is hard to tell for sure. Ferrari has spoken numerous times about its belief that it will qualify for the ADUO mechanism. It was notable that Lewis Hamilton mentioned ahead of and after the Canadian Grand Prix that he believes Ferrari has the strongest chassis on the grid, but is simply held back by its engine.
It is why Hamilton and Charles Leclerc are considered strong favourites for victory at the upcoming Monaco Grand Prix, a circuit which always benefits the team with the strongest aerodynamic package.
“The addition of the ADUO will be an opportunity for us to close the gap,” team boss Fred Vasseur said as early as March of this year. A performance boost for Ferrari might be massively significant for the Italian team if its chassis is as strong as it believes it is.
However, there’s no guarantee about any of it. Ferrari’s strong start to the year has turned out to be something of a red herring. The Italian outfit appeared to be Mercedes’ closest competitor and fought wheel-to-wheel in early rounds, but that was thanks largely in part to the lightning starts it was able to make off the grid into the lead.
Those starts are down to the smaller turbo design the engine design team opted for at Ferrari, which helped its cars launch far earlier and with much greater acceleration off the line. But that design has also been problematic, as the package has struggled to match the overall grunt of the Mercedes ICE. Whether Ferrari sticks to that smaller turbo design in future engine upgrades remains to be seen.
And what about Red Bull and Audi?
While easy to look at the start of the season and assume Ferrari is Mercedes’ next closest competitor, that might not quite be the case. Leclerc said he felt it was a no-brainer that Ferrari would be given extra help through ADUO, given the obvious advantage of Mercedes and one other manufacturer over Ferrari.
“I think it’s going to be very difficult [to catch Mercedes],” Leclerc said. “I think they have a very big advantage. ADUO ... I obviously don’t know yet if we are in.
“I’ll be surprised if not because I can see sometimes in the straight that we are lacking a little bit compared to the Mercedes or even Ford [Red Bull] power unit -- I think it will definitely be a help to try and get closer. Whether it will be enough to close the gap, I don’t know. It also depends which level we get, if we get it at all, but surely if we get it, it will be a help to get closer.”
The mention of Red Bull’s power unit there was notable and another fascinating part of the whole equation. Mercedes boss Toto Wolff raised eyebrows early in preseason when he said it was Red Bull’s brand new engine, officially dubbed Red Bull Powertrains, not his team’s, which was the benchmark.
Red Bull struggled horribly at the first few races, but there has been a marked recent improvement, which culminated in a Max Verstappen podium at the Canadian Grand Prix. Many in the paddock share the belief that, in terms of outright power, Red Bull’s engine -- built in conjunction with Ford -- might well be somewhere between Mercedes and Ferrari’s. That’s no mean feat considering it was a project built from the ground up.
Sources have suggested to ESPN that Red Bull might be the only manufacturer behind Mercedes to not be afforded ADUO, although Red Bull has hinted at anticipating that it will fall in the 2% bracket of ADUO. Ferrari could be another step below that, in the 2 - 4% bracket.
As for Audi, which joined this year, its engine has been stronger than many expected from an incoming manufacturer, but it is likely to be in the same ballpark as Ferrari when it comes to where it will rank on the FIA’s ICE Performance Index, maybe even slightly ahead.
Will ADUO be a game changer?
This is at the heart of the controversy around the mechanism. Clearly, Ferrari does not think it will be insignificant, otherwise it would not have spent so long talking about it in the press. Mercedes has been wary of the rule significantly altering the competitive order we have seen so far.
“The principle of ADUO was to allow teams that were on the back foot in terms of the power unit to catch up, but not to leapfrog,” Wolff said earlier this month. “And it needs to be very clear that whatever decisions are being made, whichever team is granted ADUO, that any such decision may have a big impact on the performance picture and on the championship, if not done with absolute precision, clarity and transparency. It needs to be clear that gamesmanship hasn’t got any place here, but it needs to be with the right spirit here that the FIA acts upon an ADUO.”
The FIA has downplayed the idea of ADUO automatically allowing manufacturers to leapfrog anyone else. The governing body’s single-seater director, Nicholas Tombazis, said earlier this month: “It’s not a magic bullet, or like the FIA is handing out brownie points to somebody who’s behind, it simply provides them with leeway to develop their power unit within the framework laid out by the technical regulations.”
Time will tell whether ADUO makes a big difference to the manufacture(s) that do end up receiving it at this stage in the season. There’s no guarantee that manufacturers will be able to make significant improvements -- either in the short or long-term -- ADUO only gives those manufacturers a bit of extra wiggle-room financially to make changes.
F1’s rules for manufacturers are important here, too. They can technically all spend as much as they want outside of the cap -- a part only falls under the manufacturer cap once a new part or upgrade is used.
So, have manufacturers already been working on potential upgrades?
Yes -- those that have anticipated receiving help through the ADUO rule have been, adding another fascinating point to the whole thing. Assuming it’s granted the ability to do so under ADUO, any manufacturer given the leeway could introduce a brand new, upgraded engine as early as the Monaco Grand Prix.
The Monte Carlo circuit is not one where a new engine would make a major difference, but would give any teams a chance to stress-test its engines ahead of the Spanish Grand Prix in Barcelona a week later.
This could be a hornet’s nest. A major improvement from a team like Ferrari would likely incense Mercedes, which has repeatedly warned that ADUO could be used for more than simply helping teams out of a bothersome situation with its engines. “I would be very surprised, actually, and disappointed if ADUO decisions that were made would come up with any interferences into the competitive pecking order as it stands at the moment,” Wolff said earlier this month.
So watch this space: ADUO might sound slightly convoluted and confusing, but it will be the dominant F1 topic for the next few races at the very least.
