When are engine brakes activated?

Engine brakes are primarily designed to assist with reducing vehicle speed by utilizing the engine's compression to slow down the vehicle without necessarily using the traditional braking system. The activation of engine brakes occurs when pressure is released from the accelerator pedal. This action signals the engine to engage the compression release mechanism, which effectively creates a resistance or braking effect.

This process is particularly useful during descents or when slowing down from high speeds, as it reduces wear on the service brakes and maintains better control without overheating the brake components. Understanding this operational characteristic is crucial for safe driving practices, especially in heavy vehicles or when navigating steep grades.