The governing body has released the findings of its most recent evaluation of the Additional Development and Upgrade Opportunities (ADUO) for Formula 1 engines, with Red Bull-Ford maintaining its status as the performance standard.
Based on the FIA’s assessment, which spans the period from the opening round in Melbourne up to the eleventh race in Budapest, the combustion engine developed by Red Bull-Ford ranks as the most potent in the sport.
Mercedes is trailing by a margin of 2% to 4% in power, whereas Audi, Ferrari, and Honda lag behind by over 4%; this evaluation did not factor in the updated engine from the Japanese brand that debuted during the recent Dutch Grand Prix.
Following the initial segment of the 2026 campaign, Mercedes was allocated a single extra homologation slot for both 2026 and 2027, whereas Audi, Ferrari, and Honda were each given two for the current and subsequent years. These allowances provide extra budget cap flexibility and additional dyno testing opportunities.
Nevertheless, a formal declaration had not been issued. Although the FIA validated the current ADUO standings on Wednesday, August 26, no further homologations were handed out during this cycle.
“The FIA conducted a comprehensive and deep analysis within our ADUO assessment procedure,” remarked Nikolas Tombazis, the single-seater director for the governing body.
Lewis Hamilton of Ferrari beside Red Bull Racing’s Max Verstappen
Image credit: Andy Hone/ LAT Images via Getty Images
“Following the publication of the Period 2 results, we are certain that the high-grade data has yielded an exceptionally solid analysis, leaving us with great certainty regarding these outcomes.
“Furthermore, we must honor the proprietary information and intellectual rights of both the competitors and their engine suppliers when sharing any specifics from these assessments.
“As this marks the inaugural year of the ADUO system, there are predictably aspects we might refine going forward, following consultations with the various engine builders.”
The ADUO framework has faced its share of detractors, with a primary flaw being its exclusive focus on the internal combustion block, failing to account for other critical performance factors within modern F1 hybrid systems.
It has been widely believed that Mercedes, rather than Red Bull-Ford, possesses the most potent power unit—an opinion openly shared by Silver Arrows chief Toto Wolff, although his remarks likely overlooked the specific context of the ADUO evaluation.
Red Bull, in particular, has expressed frustration over the restricted options provided by the current tier list, prompting them to appeal for a reassessment of the standings after the Canadian race, which was ultimately rejected.
“Toto’s assessment is correct. In my view, they indeed possess the strongest engine package,” commented Red Bull chief Laurent Mekies following the Belgian Grand Prix.
“They undeniably enjoyed a substantial speed advantage along the straights once more during this event.
“However, this is not a one-off occurrence. They hold a straight-line edge on the majority of tracks, and it was even more pronounced here due to circuit characteristics. As noted, the second assessment phase wraps up in Budapest in a week, and we shall observe the outcome.”
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