Final answer:
Use a low gear to slow your vehicle when going downhill to help control speed and protect the braking system from overheating.
Step-by-step explanation:
You should use a low gear to help slow your vehicle down primarily when going downhill. This technique, known as engine braking, allows the engine's compression resistance to help reduce the speed of the vehicle, thereby minimizing the reliance on the brakes and reducing the risk of brake failure due to overheating. When driving at high speeds or approaching a stop sign, it's customary to use the brakes to reduce speed or come to a stop.
Using a low gear for acceleration from a stop is not correct; instead, low gears are used to begin movement and then sequentially shift up to higher gears as the vehicle gains speed.
You should use a low gear to help slow your vehicle down when going downhill, approaching a stop sign, and when driving at high speeds. Using a low gear when going downhill helps to provide more engine braking and control, preventing the vehicle from gaining too much speed. Using a low gear when approaching a stop sign allows the engine to slow down the vehicle gradually instead of relying solely on the brakes, which can help prevent excessive wear and tear on the braking system. Using a low gear when driving at high speeds can help control the speed and prevent overheating of the brakes.