F1 Bahrain test: Mercedes explores new rear wing solution with twin flaps. Mercedes introduces a bold new rear wing solution on the W17 during Bahrain testing.

F1 | Unusual Mercedes: two flaps appear on the W17 to extend the rear wing

Mercedes brought an innovative rear wing solution to Bahrain, featuring two small flaps mounted on the final element that effectively extend the wing beyond the endplate height. The concept works within a previously unexplored area of the regulations and helps generate additional downforce when the wing is closed.

The final day of Formula 1 testing in Bahrain is delivering not only interesting lap time comparisons, with teams focusing on race simulations in the afternoon, but also significant technical talking points. The spotlight is firmly on Mercedes, which has introduced a never-before-seen solution — not only on the W17, but across the entire grid.

Two small “horns” appeared this morning on the rear wing of the Brackley-based car. These additional flaps are positioned at the outer edges of the wing and are attached to the last element, extending it vertically beyond the endplate and therefore operating in a regulatory area that teams had not previously exploited.

In practical terms, it is as if Mercedes has added an extra flap in sequence beyond the two main elements. The twin “horns” are not carved out of the extension of the final element itself, but rather consist of two separate small flaps mounted directly onto the last profile, also creating a dedicated blowing effect.

While part of this extension is anchored to the fixed section of the wing — the portion that integrates the rotation pivot as mandated by the regulations — the main section is connected to the movable flap. This means that when the wing is closed, the extensions contribute to generating more downforce. When DRS is open, however, the additional drag remains minimal: most of the two “horns” move together with the flap, guiding and accompanying the exiting airflow.

This is an extremely interesting solution on several levels. First of all, it shows that Mercedes has found a way to work on local volumes within what is an especially tight regulatory box this year. In such a restrictive framework, extracting extra load from the rear wing — useful for stabilising the rear end through corners and under traction, especially when electrical boost kicks in and tyre stress increases — could represent a valuable performance gain.

The other key aspect is that this region of the rear wing plays a crucial role in the overall aerodynamic behaviour of the car’s rear. The 2022 regulations had limited the use of extended endplates to such an extent that they were effectively integrated into the mainplane, making airflow management more complex. For that reason, several unusual solutions emerged in 2022, such as Aston Martin’s high-downforce configurations on specific circuits, which cleverly attempted to replicate part of the traditional endplate effect.

By contrast, the 2026 regulations have granted greater freedom in this area, allowing the return of more “traditional” endplates designed to prevent airflow from spilling outward. In this context — and considering the specific geometry of the flaps — being able to effectively extend wing elements in that zone to generate additional load becomes a particularly attractive option.

It is therefore no surprise that the endplate itself has also been redesigned. The outer strip now features a more sculpted and three-dimensional geometry compared to the previous, almost vertically flat specification. In some respects, this echoes what has been seen on front wing endplates, where teams are working to enhance the outwash effect. At the rear, similar efforts focus on managing the vortices generated in the upper section, near the tip of the endplate.

The new Mercedes rear wing specification — on which mechanics applied flow-vis paint this morning for standard aerodynamic data collection — confirms how the latest chassis regulations are unleashing engineers’ creativity. Despite the FIA’s restrictions, teams are finding increasingly inventive ways to explore and maximise every millimetre of the regulatory boxes.

Mercedes has therefore introduced a highly innovative “horned” rear wing design in Bahrain, utilizing additional mini-flaps to extend the wing’s effective surface area and generate crucial downforce without a significant drag penalty during high-speed DRS activation.