What gear should be used when driving downhill?
2 Answers
For automatic transmission vehicles, the gear selection should be adjusted according to the slope gradient. Use lower gears for steeper slopes and higher gears for gentler slopes. Here are the relevant details: 1. For manual transmission vehicles, when facing a long or steep downhill slope, you can shift into D2 or D3 to control the gear. D2 means the transmission will not shift beyond 2nd gear, while D3 limits it to 3rd gear, allowing you to effectively utilize the engine's traction to control the vehicle speed. 2. The principle of engine braking: Engine braking refers to the drag effect created by the compression resistance, internal friction, and intake/exhaust resistance generated during the engine's compression stroke on the driving wheels (manual transmission vehicles can be parked on a slope by leaving them in gear, utilizing this principle).
When I used to drive long-haul trucks, I always shifted to lower gears to control speed on downhill slopes. For automatic transmissions, I'd use L or manual mode to shift to second gear; for manual transmissions, I'd directly downshift to second gear. This way, the engine helps slow down the vehicle, reducing brake usage. Don't underestimate this technique—brake pads can overheat if used excessively on steep or long downhill sections, and failure can lead to accidents. I've seen many accidents caused by relying solely on brakes. That's why I always shift gears before descending, maintaining a steady speed. Engine braking is not only safer but also extends brake life. New drivers just need to practice a few times—remember, never coast in neutral, it's too dangerous. The key is protecting yourself and your vehicle.
