Which gear should be used for automatic transmission when going down a long slope?

[StBethany]

When going down a long slope with an automatic transmission, you should shift to the low-speed L gear, or switch to manual mode to downshift manually or use the sport S gear. The reasons why it is not recommended to use the D gear when going down a long slope are as follows: 1. When going downhill, the vehicle has acceleration, and the D gear will make the vehicle speed faster: When going downhill, if the component force along the slope direction is greater than the resistance, longitudinal acceleration will be generated. At this time, if the D gear is engaged, the vehicle speed will increase more rapidly. 2. Frequent braking is required to control the speed: When the vehicle speed is high, frequent braking is often required to reduce the speed. 3. Frequent braking can easily lead to brake failure: Frequent braking will cause the brakes to overheat, and when the brake pads reach excessively high temperatures, their braking ability will decrease, leading to ineffective braking. Therefore, when going down a long slope, shifting to a lower gear can reduce our safety risks.