What gear should an automatic transmission use when climbing a steep slope?

[DylanDella]

When climbing a steep slope with an automatic transmission, use the L gear. If there is no L gear, you can use the S gear or M gear. The L gear is the low gear. After shifting into this gear, the transmission will maintain a lower gear without upshifting, which can increase the torque on the wheels, allowing the vehicle to climb the slope smoothly. The M gear is the manual mode of the automatic transmission. After shifting into this gear, the driver can lock the transmission in a relatively low gear, which also increases the torque on the wheels to help the car climb the slope smoothly. The S gear is the sport mode. After shifting into this gear, the transmission will also maintain a lower gear without upshifting, allowing the vehicle to climb the slope smoothly. An automatic transmission does not require the driver to manually shift gears; the vehicle will automatically select the appropriate gear based on the driving speed and traffic conditions.

[WalterMarie]

Having driven automatic transmission cars for over a decade, my experience with steep slopes tells me it's best to shift to a lower gear rather than just using D gear. D gear is suitable for flat roads or gentle slopes, but on steep inclines, the car tends to shift gears frequently, resulting in weak engine power and a higher risk of rolling back. I recommend switching to L gear (Low gear), which locks the engine in a lower gear, providing stronger torque output for stable climbing without rolling back. Some car models have S gear or M gear, which work similarly—manually selecting a lower gear in manual mode. Choose the appropriate gear before climbing and avoid shifting midway for safety. When stopping at the top of the slope, firmly apply the brakes and use the handbrake to secure the car. Additionally, ensure good tire traction, and be extra cautious on slippery surfaces to avoid sudden acceleration that could cause skidding. For added safety, hill-start assist can be a great help, but don’t rely on it entirely.