How to Use the D and S Gears in an Automatic Transmission?

[SanJoy]

How to use the D and S gears in an automatic transmission: 1. When using the D gear in an automatic transmission car, the onboard computer will automatically control the car's gears according to the pre-set program. During driving, the car will shift up and down completely based on the pre-set program; 2. While driving, switching to the S gear does not require pressing the brake pedal or decelerating. The D gear in an automatic transmission is the forward gear, and this gear is also the most frequently used one. The S gear is the sports mode in the car. When using the D gear, the engine speed does not rise particularly high during gear shifts in the automatic transmission. When the engine reaches an appropriate speed, the automatic transmission will shift gears automatically. Switching to the S gear sports mode while driving will cause the engine speed to rise instantly. This mode is generally not used frequently and is only employed during overtaking or when driving on uphill sections.

[VanJocelyn]

When driving an automatic transmission car, I basically use the D gear for everything. Whether it's commuting in traffic, picking up the kids, or daily grocery runs, keeping it in D gear is sufficient, and driving gently on the throttle saves a lot of fuel. However, when I need to overtake or climb a long slope, I directly switch to S gear. At this point, the car's RPM immediately increases, the power response becomes much quicker, and stepping on the throttle gives a noticeable push-back feeling. Remember to switch back to D gear after use, otherwise, the fuel consumption will rise rapidly. I once tried driving 50 kilometers of mountain roads continuously in S gear, and the fuel gauge dropped visibly fast.

[RuthDella]

I'm a pretty casual driver. In the city, I just keep it in D mode all the time, smooth as an electric car. Occasionally, when I want some driving fun—like passing trucks on the highway or tackling steep garage ramps—I switch to S mode for a thrill. No need to hit the brakes when shifting; just flick the paddle and you're good. Last time on a mountain road, I tried S mode through continuous curves—the transmission automatically held lower gears at higher revs, making cornering super stable. But on regular flat roads, S mode is overkill. It keeps revs stubbornly above 3000 rpm, wasting gas and making a racket.

[LeOmar]

D mode is the ultimate tool for daily commuting, offering worry-free operation, fuel efficiency, and smooth performance. Once I drove from Beijing to Tianjin entirely in D mode, averaging just 6.7L per 100km. S mode, on the other hand, is designed for special road conditions, such as navigating flooded areas during heavy rain or accelerating sharply to escape icy surfaces. In S mode, the transmission delays upshifts, keeping the engine in the optimal power band of 2000-4000 RPM. I remember being stuck behind a truck on a steep slope; switching to S mode and hitting the throttle allowed me to surge ahead noticeably faster than neighboring cars using D mode.

[DeLeo]

Nowadays, automatic transmission cars basically have this configuration. When teaching my daughter who just got her driver's license how to use the car, I said: Remember to shift to D gear when the traffic light turns from red to green, and shift to S gear when you want to overtake. D gear is the intelligent mode, where the car matches the gears by itself, suitable for driving at a steady speed below 60 km/h. S gear is equivalent to the 2-3 gears of a manual transmission, with greater torque output. The most common mistake beginners make is using D gear all the time on long downhill slopes. In fact, switching to S gear to use engine braking is safer at this time. I drive on mountain roads every week and always switch to S gear on downhill sections, so I don't have to step on the brakes all the time.

[OKinsley]

For 95% of daily driving situations, using D mode is sufficient. Once a friend borrowed my car for a road trip and complained about high fuel consumption upon return—turned out he drove the entire highway trip in S mode. Actually, S mode is most suitable for two scenarios: when engine braking is needed for continuous curves on mountain roads, or when greater torque is required for climbing steep slopes with a full load. I remember once carrying four colleagues up a resort's 30-degree slope—switching to S mode made it effortless, whereas D mode would have left the engine struggling. Remember not to misuse S mode in city driving—it not only wastes fuel but also increases the risk of carbon buildup.