Should I use S gear or D gear when driving uphill with an automatic transmission?

[ORobert]

When driving uphill with an automatic transmission, the gear lever should be placed in the D position. Here are a few key points to note: 1. When ascending a slope, keep the gear in D position and adjust the throttle according to the steepness of the slope. Remember to decelerate when approaching the crest as visibility is limited, and be cautious of oncoming vehicles. 2. For a pure automatic transmission, simply using throttle control is sufficient. If pressing the accelerator deeply doesn't provide enough power, the vehicle will automatically force a downshift. Once speed increases, it will automatically upshift. For vehicles with manual-automatic transmission (tiptronic), use the '+' and '-' symbols on the gear panel - after locking, push towards '+' to upshift one gear and towards '-' to downshift one gear.

[Lila]

I love using the S gear when driving uphill, especially on those long and steep slopes. The S gear keeps the RPM higher, making the engine deliver more power, which feels particularly strong when climbing. If I use the D gear, the transmission keeps shifting up and down automatically, making the car feel like it's hiccuping, with very noticeable jerks. Actually, the S gear in an automatic transmission is equivalent to the lower gears in a manual transmission. It can also be used downhill to utilize engine braking and reduce pressure on the brake pads. However, for gentle slopes, just stepping on the throttle in D gear is enough—switching gears back and forth is just a hassle.

[EllianaLynn]

Those who frequently drive on mountain roads know that the S gear is the way to tackle steep slopes. This gear locks the transmission in the lower gear range, maintaining high RPMs to deliver maximum torque, ensuring the car doesn't falter when climbing. Using D gear, the transmission constantly seeks to upshift for fuel efficiency, resulting in fluctuating RPMs during climbs—the engine roars but the speed barely increases. I remember two years ago when I drove the Sichuan-Tibet route, conquering the long slopes of Zheduo Mountain entirely in S gear. Some high-end cars even have dedicated hill-climbing modes, but for regular vehicles, S gear works just as well—it can truly prevent dangerous rollbacks in critical moments.

[SanEden]

Using D gear is perfectly fine for small slopes on regular city roads, but when encountering steep slopes like underground garages, it's recommended to switch to S gear. This is because greater traction is needed in such situations, and S gear delays the shifting timing to allow the engine to exert more power. If you're driving a car with paddle shifters, manually selecting 2nd gear is also an option. Remember to switch back to D gear after climbing the slope to save fuel, and you can also utilize the drag effect of S gear to protect the brakes during long downhill descents. Experienced drivers will prepare for gear shifts before noticeable changes in slope, rather than scrambling when the car starts to lose power.

[DelVera]

There is a significant difference between the D (Drive) and S (Sport) modes in automatic transmissions when going uphill. The D mode features intelligent gear shifting, which may cause frequent shifts between 2nd and 3rd gears on slopes, leading to unstable speed and higher fuel consumption. In contrast, the S mode keeps the engine RPM above 3000, delivering power similar to manually shifting into 2nd gear, providing consistent strength during climbs. Especially when climbing with a full load and air conditioning on, switching to S mode noticeably enhances the car's confidence. However, some vehicles may downshift faster in D mode during sudden acceleration, but S mode remains more reliable for uphill driving. Remember to ease off the throttle slightly when switching modes to avoid transmission shock.

[OEden]

I've seen mechanics inspect transmissions after continuous uphill driving and found that vehicles frequently using D gear on steep slopes show significantly more wear. Due to D gear's automatic upshift feature, it constantly shifts gears on roads with large gradient changes, causing fluctuating valve body pressure. Switching to S gear avoids this issue by keeping the transmission steadily in lower gears. This trick is especially effective for CVT models to prevent belt slippage. Of course, D gear is sufficient for gentle daily slopes. But if you hear the engine roaring without much forward movement, it's time to decisively switch to S gear.