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

You answered correctly. The permanent brake, also known as the retarder, is designed to provide continuous braking power without causing wear because it operates differently from the regular service brakes, which use friction. Using the retarder helps to relieve the service braking system, especially on long descents, reducing wear and the risk of overheating. However, a retarder cannot bring the vehicle to a complete stop; it is mainly for speed control and supporting the main braking system. Knowing how to use the retarder helps preserve the main brakes and makes driving large vehicles safer and more efficient.