Ferrari PU deficit: What is causing the SF-26 horsepower shortage. Analysis of Ferrari's engine performance deficit .

Ferrari is awaiting the FIA’s ADUO verdict as the Scuderia looks for an opportunity to intervene on its 2026 Formula 1 power unit.

Why the Ferrari SF-26 appears to have a horsepower deficit

Formula 1 is preparing for the fifth round of the 2026 world championship in Canada, after which the FIA will determine which engine manufacturers will be allowed to intervene on their power units — and to what extent — under the first ADUO evaluation window.

Ferrari is now waiting to discover which performance bracket it will be placed in, which will determine both the additional budget available and the number of development interventions it will be allowed to make in 2026 and 2027.

The Maranello-based team is widely believed to be operating at a clear power unit performance disadvantage compared to Mercedes.

The latest issue of Autosprint suggested that the root of this horsepower deficit could lie in either a design miscalculation or an imperfect compromise in the long-standing tug-of-war between Ferrari’s aerodynamic department and engine engineers.

According to a report from Corriere della Sera, the delay in Ferrari’s power unit performance may stem from an incorrect assessment of the energy efficiency achievable inside the combustion chamber.

“The initial concept developed during the early years of the study reportedly revealed major critical issues and failures,” the report states. “There were difficulties in combustion management and thermal degradation beyond expectations. At the core of the issue may have been an overly optimistic evaluation of the energy efficiency that could be achieved inside the combustion chamber.”

“Following Wolf Zimmermann’s departure, the department led by Enrico Gualtieri was given greater authority to correct the direction, although it still had to operate within the significant constraints imposed by the budget cap and under extremely tight timeframes.”

Ferrari’s current power unit deficit therefore highlights the immense technical challenge of the 2026 engine regulations, leaving Maranello completely reliant on the upcoming FIA equalisation framework to unlock the competitive potential of the SF-26 project.