Pull the steering wheel backward, and the front wheels instantly turn toe-in. This was the “black technology” that Mercedes introduced in 2020, shocking the paddock before being banned shortly afterward. In today’s F1 science explainer, let’s uncover the mystery of the system known as DAS.
First, what exactly is the DAS system? DAS stands for Dual Axis Steering, a revolutionary innovation first revealed by Mercedes during pre-season testing in 2020. In simple terms, it allowed drivers to push or pull the steering wheel to dynamically adjust the toe angle of the front wheels, essentially adding an extra axis of control to optimize tire behavior and improve overall efficiency.
To understand DAS, we first need to clarify the concept of toe angle, a key parameter in car setup. Toe angle is the angle of the wheels relative to the car’s longitudinal axis when viewed from above, measured in degrees or millimeters. It should not be confused with camber, which is measured from the front or rear of the car relative to vertical.
Toe angle has three main types:
-
Zero toe – wheels are perfectly straight, parallel to the longitudinal axis.
-
Toe-in (positive toe) – wheels angle inward, forming a pigeon-toed “V” shape.
-
Toe-out (negative toe) – wheels angle outward, forming an inverted “V” shape.
Most of the time, F1 cars run toe-out at the front wheels to improve responsiveness and agility during corner entry. Although adjustments are usually tiny—within 2 degrees—even small changes significantly affect performance. The revolutionary aspect of DAS was that it allowed drivers to adjust toe angle while driving.
So what does changing the toe angle achieve? Primarily, it helps optimize performance on different parts of the track and manage tires more effectively.
-
On long straights: Drivers pulled the steering wheel back, moving the toe angle closer to zero or even slight toe-in. At near-zero toe, rolling resistance is reduced because lateral drag decreases. With slight toe-in, the wheels naturally align toward the centerline, counteracting road disturbances or suspension deflection, making the car more stable at high speeds. Also, since F1 cars typically run with large negative camber, combined with standard toe-out, the inner shoulders of the front tires suffer more stress and friction. Adjusting to zero or toe-in reduced that inner wear and lowered tire temperatures on straights.
-
In corners: Drivers pushed the steering wheel forward, returning the wheels to toe-out. This outward angle helped the inside wheel point more aggressively into the corner apex, improving grip, responsiveness, and cornering speed, thereby stabilizing the car during entry and mid-corner.
-
For tire temperature management: During formation laps or after safety car periods, DAS helped balance heat across the tire surface. Toe-in increased heating on the outer edge, toe-out warmed the inner edge, and zero toe cooled overheated zones. This fine control allowed the tires to stay in their optimal working range longer.
However, DAS only lasted one year before being banned. Its legality caused major controversy when it debuted. Red Bull’s Christian Horner questioned whether it was a movable aerodynamic device or violated rules prohibiting suspension adjustments during races. Some also worried the extra driver input could distract from safety.
Although the FIA deemed DAS legal in 2020, they decided to ban it from 2021 onward. The new rule required that wheel alignment could only be controlled through rotation around a single steering axis, effectively eliminating DAS.
Thus, DAS shone briefly in F1 but remains a prime example of innovation at the very edge of regulations. Teams constantly push boundaries in pursuit of ultimate performance, and history has seen many such “black technologies” like the double diffuser, fan car, six-wheeled cars, and the F-duct—brilliant innovations that were eventually outlawed.
🛒 Shop Now & Choose your F1 Model！
