Mercedes Declines ADUO Upgrade Despite 2% Performance Gap to Red Bull

Mercedes is sitting out the ADUO upgrade race, even though its engine is running 2% behind Red Bull’s benchmark. The reason? The team has decided reliability matters more than chasing pace right now.

The FIA has confirmed Mercedes’ internal combustion engine trails Red Bull by at least 2%, which qualifies them for the ADUO allowance—a special program that offers extra spending and test bench hours for one new homologation in 2026 and another in 2027. Ferrari and Audi have already tapped their ADUO allocations to roll out fresh power units, but Mercedes is holding back.

At the Austrian Grand Prix, Mercedes did introduce new Formula 1 engines—but not upgraded ones. George Russell and Kimi Antonelli both received fresh power unit components: new internal combustion engines, turbochargers, batteries, and control electronics. The real priority was sorting out reliability. Russell hit trouble in Canada and Antonelli in Barcelona, both sidelined by battery failures, so Mercedes needed to fix these issues before they cost more races.

Team principal Toto Wolff was straightforward about it: “No, they were just new power units. With that comes less mileage, comes a little bit more spiciness. But there was no upgrade in it, and at the moment there’s no upgrade planned.” Yes, the fresher hardware does squeeze out a small gain—Wolff called it “a little bit more spiciness”—but durability was the real target.

The picture could shift soon. The FIA plans to review all power unit performance between Monaco and Hungary to check if anything has changed in the standings. Red Bull is pushing the FIA to overturn its original pre-Canada ranking that put them at the top, and they’ll stay ineligible for ADUO until a rival has beaten them by at least 2%.

Mercedes isn’t standing still. Customer teams will start getting fresh power unit components over the coming races, a sign the team is building improvements step by step. For now, they’re betting that playing it steady and stacking small gains will work better than rushing into a new homologation.