What is the correct method to control speed when descending a long slope?
2 Answers
When descending a long slope, the correct methods to control speed are: 1. For manual transmission vehicles, shift the gearbox to a lower gear to utilize engine braking, while also applying the brakes to maintain a reasonable speed range; 2. For automatic transmission or semi-automatic vehicles, switch the gearbox to manual mode and select a lower gear, or shift to L (Low) gear if available, using the gearbox braking in combination with the brakes to control speed. When descending, the gear selection should be based on the slope gradient—the steeper the slope, the lower the gear should be. Essentially, the lower gear helps to restrain the vehicle's speed from becoming too high, avoiding prolonged use of brakes which could lead to brake component damage.
When going down a long slope, the most important thing is to avoid prolonged braking, as it can cause overheating and failure. Once, I drove a manual transmission car downhill and directly shifted to a lower gear, using the engine to slow the car down. It's fine if the tachometer runs a bit higher—engines are built tough. For automatic transmission cars, shift to L gear or manual mode. Some vehicles even have a hill descent control feature; turning it on lets the system automatically regulate the speed. Keep an eye on the rearview mirror at all times to check if any large trucks are following too closely. If the speed still starts to climb, quickly use intermittent braking to slow down—never slam on the brakes. It's best to pull over periodically to let the brake pads cool off. If the wheel hubs feel hot to the touch, wait for them to cool down before continuing.
