Here’s what the intriguing holes in Mercedes’ and Ferrari’s F1 diffusers are for
Formula 1 teams are entering a new era of competition with the 2026 season, bringing significant regulation changes. As is typical, initial launches and track testing are often strategic, with teams carefully revealing information to avoid giving rivals an advantage. Red Bull Racing, for example, previously showcased differing designs during launches and subsequent testing to obscure their true development path.
Early Insights from 2026 Testing
Despite the inherent secrecy, early runs with the 2026 cars are already revealing key trends. Several teams are revisiting a higher rake philosophy, reminiscent of designs used up to 2021. A return to pushrod front suspension is also becoming apparent across multiple teams. Notably, Ferrari has demonstrated the functionality of active aerodynamics on track for the first time.
The Diffuser Challenge
A significant area of focus is the diffuser, impacted by simpler floor designs mandated by the 2026 regulations. These simpler floors generate less downforce than previous ground-effect systems, making efficient diffuser design crucial. Initial observations of the Mercedes W17 during a shakedown revealed an opening in the diffuser, resembling ‘mouse holes’ seen in earlier designs, but larger in size. A similar feature was subsequently observed on the new Ferrari SF-26 at Fiorano.
The prevailing theory is that this diffuser opening works in conjunction with undercut sidepods, directing airflow underneath the car and over the floor edges. By channeling airflow through this opening, teams aim to enhance diffuser performance and generate more downforce, preventing airflow detachment.
The Return of ‘Inwash’
Another evolving design element is the resurgence of barge boards, though with a different purpose than previously seen. While historically used to create ‘outwash’ – directing wake from the front tires outwards – the FIA now intends these elements to function as ‘inwash’ devices. The primary design requirement is for the main element to point inwards, reducing the impact of turbulent air on following cars.
Teams are working to minimize the amount of disturbed airflow drawn inwards, and several solutions are already visible. This airflow impacts both the floor and diffuser performance, prompting teams like Mercedes and Ferrari to explore methods of channeling airflow from the sidepods towards the diffuser opening.
Stronger airflow in this area could also help mitigate ‘tyre squirt’ – the turbulent air released from the rear tires that can negatively affect diffuser performance. By managing this airflow more effectively, teams hope to achieve a dual benefit.
Industry Reaction
The approach taken by Mercedes has garnered attention from other teams. David Sanchez, technical director of Alpine, described it as “a bit unusual, it’s an interesting interpretation, but not a total surprise” during his team’s launch in Barcelona. He also emphasized the ongoing development expected in the area of the diffuser and its interaction with the bodywork and rear corner of the car.
Frequently Asked Questions
What is ‘rake’ in Formula 1?
Rake refers to the angle of the floor relative to the chassis. A higher rake angle means the floor is positioned higher at the rear, influencing airflow under the car.
What is ‘active aerodynamics’?
Active aerodynamics refers to aerodynamic elements that can change their shape or configuration during a race to optimize performance, as demonstrated by Ferrari.
What is ‘tyre squirt’?
Tyre squirt is the turbulent air that comes off the rear tyres and moves sideways, which can negatively affect the performance of the diffuser.
As teams continue to refine their designs and gather data, it will be fascinating to see how these early concepts evolve and impact the competitive landscape of the 2026 Formula 1 season.