When to Use S and L Gears in an Automatic Transmission?
2 Answers
Automatic transmission S gear is typically used for overtaking or climbing hills due to its stronger power output. After completing these maneuvers, it is advisable to switch back to the more economical D gear. In terms of fuel consumption, the S gear mode consumes more fuel than the normal mode because of the increased fuel injection at higher engine speeds. The L gear in an automatic transmission is engaged when going downhill. In this mode, the gear is limited to a low gear (usually first gear), allowing the driver to utilize the engine braking effect of the transmission to control the vehicle's speed, thereby reducing the burden on the brakes, minimizing the risk of brake fade, and enhancing driving safety. For vehicles without an L gear, if equipped with a manual mode, the manual mode can be used for downhill driving.
I've been driving automatic transmission cars for over a decade and am quite familiar with using both S mode and L mode. S mode is most effective when overtaking on highways - once engaged, the RPM immediately rises with noticeably more responsive throttle input. Just a light press brings instant power surge, making lane changes and overtaking exceptionally stable. I also prefer using S mode when climbing steep hills, as the regular D mode tends to struggle whereas S mode delivers noticeably stronger pulling power. As for L mode, I engage it during long descents, especially on winding mountain roads with continuous downhill curves. In L mode, the engine assists with braking, reducing the need for constant brake pedal use and preventing brake pad overheating. L mode also helps with winter starts on icy surfaces by reducing wheel spin. However, these modes shouldn't be used in city traffic jams as they increase fuel consumption and mechanical wear.
