When should you downshift with automatic transmissions?

Downshifting with automatic transmissions is most important when going downhill to utilize engine braking. This technique allows the vehicle to slow down naturally by using the engine's resistance rather than relying solely on the service brakes, which can help to prevent overheating and wear. When descending, downshifting reduces the risk of losing control due to excessive speed, as it enables the engine to assist in controlling the vehicle's speed.

Utilizing engine braking through downshifting is particularly useful on steep grades or long downhill stretches, as it provides additional control and can enhance safety. This method is an important skill for commercial drivers to master, as it contributes to smoother operation and helps in maintaining safe speeds without over-depending on the brake system.