Mercedes and Ferrari have introduced intriguing holes in the diffusers of their 2026 Formula 1 cars during recent shakedowns, aiming to boost downforce under new regulations. These designs channel airflow from undercut sidepods to enhance performance amid simpler floor setups. Experts view the approach as an interesting evolution in aerodynamics.
The 2026 Formula 1 season brings radical changes to chassis and engine rules, prompting teams to rethink aerodynamics. During Mercedes' shakedown of its W17 car last week, observers spotted a large opening in the diffuser, reminiscent of past 'mouse holes' but larger. A day later, Ferrari displayed a similar feature on its SF-26 at Fiorano.
Under the new regulations, flatter floors produce less downforce than the ground-effect era of 2022-2025, where Venturi tunnels and sealed diffusers were key. Now, teams must find external airflow sources to accelerate air toward the diffuser ramp, preventing detachment and generating more downforce, much like a steep wing element. The holes work with undercut sidepods, guiding air underneath and over floor edges directly into the diffuser.
This shift addresses reduced floor efficiency, partly due to 'inwash' devices—evolved from past bargeboards—that direct airflow inward to minimize dirty air for trailing cars. Such elements inevitably disrupt floor and diffuser performance, including 'tyre squirt' from rear tires. The Mercedes and Ferrari solutions could counter these issues by strengthening airflow in the rear.
Alpine technical director David Sanchez commented on Mercedes' design during his team's launch: "It's a bit unusual, it's an interesting interpretation, but not a total surprise." He highlighted ongoing development: "The interaction between the bodywork, the diffuser, the rear corner is going to be very much a work in progress."
Caution surrounds launch designs, as teams like Red Bull have historically altered concepts to obscure rivals' views. With Barcelona shakedowns underway and more reveals imminent, diffuser optimization remains a focal point for 2026 competitiveness.