Georgia Commercial Driver License Practice Test

What is the purpose of a retarder in a truck?

1. To increase speed

2. To reduce the need for brakes

3. To assist in reversing

4. To stabilize the cargo

The correct answer is: To reduce the need for brakes

The purpose of a retarder in a truck is to reduce the need for brakes. A retarder is a device that slows down the vehicle without using the traditional braking system. By converting the truck’s kinetic energy into heat or using engine compression to assist in deceleration, the retarder helps maintain a safer speed, especially on downhill grades. This not only extends the lifespan of the brake components by reducing wear and tear but also enhances overall vehicle control and safety. A feature like this is particularly important in heavy trucks, where the sheer mass can lead to significant wear on brakes from continuous use. It offers drivers additional control, particularly in situations requiring controlled descent, allowing for a more manageable driving experience. Options suggesting that the retarder increases speed, assists in reversing, or stabilizes cargo do not accurately reflect the function of this component, as a retarder is focused solely on managing and reducing speed rather than enhancing power or stability.