Mercedes-Benz is innovating in the world of electric vehicles (EVs) with its development of a new braking system called the “in-drive brakes.” This system, designed at the company’s research and development center in Sindelfingen, Germany, integrates braking functionality directly into the vehicle’s drivetrain.
Instead of the traditional brake calipers pressing pads against a rotor, the in-drive system utilizes a circular brake pad that is directly connected to the output shaft of the electric motor. This pad is then pressed against a stationary water-cooled ring, all within an enclosed system. The beauty of this design is that it eliminates the need for calipers, rotors, and brake pads that are traditionally found at each wheel. The system is expected to function for the life of the vehicle, reducing the need for regular brake repairs and replacements—something that could save vehicle owners significant costs over time.
One of the most significant benefits of this system is that it is virtually maintenance-free. The brake dust, a common contributor to pollution in urban areas, is captured in a sealed compartment, eliminating the need to periodically clean or replace dust filters. This is especially important in cities with heavy traffic, where stop-and-go driving can lead to significant brake dust buildup. Additionally, because the in-drive brake is water-cooled, Mercedes believes brake fade—the reduction in braking performance due to overheating—will be a non-issue.
Another advantage is that by moving the braking mechanism away from the wheels, unsprung weight is reduced. Unsprung weight refers to the weight not supported by the chassis, which includes the components that move with the wheels, like the brake system. By reducing this weight, the vehicle benefits from improved handling and a smoother ride. Additionally, without the need for traditional brake rotors and calipers, the wheels could potentially be made more aerodynamically efficient.
As global regulations like the Euro 7 emissions standards, which are set to go into effect in 2026, start to take effect, the in-drive brake system also has environmental advantages. By reducing brake dust and consolidating components, the system not only reduces the vehicle’s maintenance needs but also minimizes its environmental impact, making it a step forward in the auto industry’s efforts to become more sustainable.
Mercedes-Benz is not the only company looking to revolutionize vehicle architecture. Companies like REE are rethinking the entire design of EVs, relocating motors, drivetrain, suspension, and even brakes into the wheel wells, creating a modular platform that can be used for various types of vehicles, from trucks to sports cars.
While it remains to be seen whether Mercedes’ in-drive brake system will become a standard feature across all EVs or remain a premium offering, it represents a significant shift in how we think about braking in modern vehicles.