Why should you use the permanent brake (retarder) of your motor vehicle?

The use of a permanent brake, or retarder, is important for several reasons based on German traffic regulations.

Firstly, it operates without wear, meaning it does not contribute to the wear and tear of the vehicle's standard braking system. This is particularly beneficial for prolonging the lifespan of the service brakes and reducing maintenance costs.

Secondly, the retarder can relieve the service braking device. This means that by using the retarder, you can lessen the frequency and intensity with which the mechanical brakes are engaged, which is crucial during long descents and helps prevent brake overheating.

The third option, while not included in your answer, is that the retarder can indeed bring the vehicle to a standstill. However, relying solely on it for complete braking might not be practical in all situations, which is why it's seen as a complement to the standard brakes.

Understanding these aspects helps improve safety and efficiency while driving, aligning with the principles outlined in German traffic law, ensuring vehicles can handle deceleration without undue wear or risk.