Mercedes' ADUO upgrade will not be introduced for this weekend's United States Grand Prix.

The Silver Arrows will not have its updated power unit for the upcoming race weekend at the Circuit of the Americas, GPblog can confirm. Moreover, this website understands that the introduction of the updated engine will not seem to happen in Mexico City next weekend either.

Currently, power unit manufacturers, based on their gap to the benchmark engine, can get additional development and upgrade opportunities (ADUO) for the season. Manufacturers that are found to be at least 2% behind the benchmark engine can introduce one performance update in both 2026 and 2027. If the gap exceeds 4%, they are permitted two updates during each season.

To determine which manufacturers are eligible to benefit from the ADUO system, the FIA considers only the internal combustion engine, and Red Bull Ford was declared the benchmark, allowing Mercedes to introduce an update.

Photo: Race Pictures

Russell will definitely have to take grid penalty to use the upgraded Mercedes power unit

After George Russell experienced a power unit failure at the Bahrain Grand Prix in Malaysia, he was forced to take a grid penalty for the Singapore Grand Prix. When Mercedes introduces the new ADUO package, Russell will have to take another grid penalty, as his power unit components already exceed the permitted limit.

Verstappen also says that he would have to take a grid penalty at some point

The Red Bull Racing driver was also asked about his position regarding the permitted limits for power unit components. Verstappen said: "We have to take a penalty at one point? Yeah, potentially. But there's no known date to that at the moment. So we just see what happens."