Should an automatic car use S gear or M gear when climbing a slope?
3 Answers
An automatic car should use M gear when climbing a slope. Lower gears provide stronger engine power, making it easier to complete the climb. When ascending a steep slope, placing the gear in M- will give the car more power. Scenarios where the M gear can be used in a car: when overtaking, going up or down slopes, driving on highways, or driving on icy or snowy roads. When overtaking, using the M- gear to lower the gear can provide higher torque, allowing the car's speed to increase rapidly in a short time. When climbing a slope, the car should use M- as lower gears offer stronger engine power. When descending, you can adjust the gear to 2-3 using M+ to utilize the engine's braking effect, reducing reliance solely on the brakes and enhancing driving safety. Additionally, using M gear when descending steep slopes helps control speed through engine braking, preventing brake overheating and thermal fade. When driving on highways, manually adjusting to a higher gear using M+ to maintain a speed of 80-100 km/h can improve fuel efficiency. When driving on icy or snowy roads, adjusting the gear to 2 using M+ can reduce wheel slipping.
After driving for so many years, I usually choose the S gear when driving an automatic transmission car uphill. It's actually the sport mode, which delays gear shifting to keep the engine at high RPM, providing greater torque and making climbing hills particularly powerful. Especially on gentle slopes like those on highways, shifting to S gear makes it effortless to go up. The M gear requires manual shifting, which isn't very useful for daily city driving, but it comes in handy on steep and continuous mountain roads. Like last week when I was driving on winding mountain roads, I used the M gear to lock in 2nd gear for climbing, and it felt more stable in terms of power, plus it helped with braking downhill. However, for most people, using the S gear is completely sufficient for daily use—it's simple and fuel-efficient.
I often encounter uphill driving and have used both modes. The S mode is particularly suitable for less steep slopes, where the engine automatically controls the RPM, delivering continuous and smooth power output—it's like having someone help you press the accelerator. During long road trips with rolling terrain, the S mode is the most hassle-free. On the other hand, the M mode has an advantage on extremely steep mountain roads. For example, when I traveled to Western Sichuan last year, manually fixing it in 1st or 2nd gear provided ample uphill power without any rollback. However, beginners are advised to start with the S mode, as improper use of the M mode might backfire. It also depends on the car's condition; older cars may consume more fuel in S mode, while newer models handle it just fine.
