Major engine upgrade boost to Mercedes, Ferrari, Audi, and Honda

Introduced under Article C4 of the 2026 Technical Regulations, the ADUO framework is designed to prevent a single power unit manufacturer from dominating unchecked. Any manufacturer whose internal combustion engine (ICE) falls more than 2% behind the class-leading benchmark during set evaluation windows receives extra homologated upgrades across both the current and subsequent seasons, accompanied by expanded dyno hours and cost cap increases.

Following the opening review period, which concluded after the Canadian Grand Prix, analysis confirmed that Mercedes sat between 2% and 4% adrift of the top-performing ICE. As a result, the Brackley-based outfit is permitted one additional homologation in 2026 and another in 2027, backed by matching cost cap and dyno adjustments.

Meanwhile, Ferrari, Honda, and grid newcomer Audi were each determined to be trailing by more than 4% compared to the leading ICE. Due to that steeper deficit, all three manufacturers have been granted the maximum concession of two additional homologations for 2026 and two for 2027, along with significant testing and spending allowances.

By contrast, the second review period, which wrapped up after the Hungarian Grand Prix, saw no further homologations granted to any manufacturer on the grid, suggesting engine output margins tightened through the early summer stretch.

FIA Single-Seater Director Nikolas Tombazis emphasised the rigour behind the assessment while maintaining manufacturer confidentiality:

The paddock will now turn its attention to the third 2026 ADUO review period, which evaluates rounds 12 through 18, spanning from the Dutch Grand Prix to the Mexico City Grand Prix.