Do You Need to Press the Brake When Shifting from D to S Gear?

[LondynRose]

Shifting from D to S gear does not require pressing the brake. Situations where you need to press the brake when shifting gears are as follows: 1. Shifting from P gear to any other gear requires pressing the brake. This is a safety feature to ensure driving safety. Otherwise, when shifting from P to R or D, the car immediately gains backward or forward driving force. The handbrake alone may not be sufficient to stabilize the car, which could lead to danger. If the accelerator is accidentally pressed at the same time, even pressing the brake afterward might sometimes be too late, easily causing accidents involving people or facilities. 2. D-N, R-N: When shifting an automatic transmission car from D or R gear to neutral, it is best to bring the car to a complete stop before operating, during which the brake should be pressed. This is because the gear positions in an automatic transmission are controlled by the clamping and releasing of one-way clutches. Different gears in an automatic transmission are achieved through planetary gear mechanisms, where locking the planetary gears, sun gear, or planetary carrier with gear clutches results in different gear positions. Gear clutches consist of multiple friction plates and pressure plates, with the friction plates connected to the planetary gear mechanism and the pressure plates connected to the transmission housing.

[RachelRose]

My fifteen years of driving automatic transmission experience tells you that shifting from D to S doesn't require braking at all! Watch how I usually overtake by directly flipping the gear lever - the transmission is smart enough. Sport mode is designed for instant switching, manufacturers already considered dynamic shifting needs during design. But be aware that suddenly shifting to S at very high speeds will make the engine abruptly rev up, causing a sudden jerk. Recommended to shift below 80km/h for smoother transition, and remember to turn off adaptive cruise control first. Actually, shifting to S during rainy day overtaking is particularly effective, as delayed upshifting helps reduce wheel slip.

[MacNadia]

I work in auto repair, let me explain the principle. The transmission control unit has a protection program. Both D and S gear signals are sent to the same control module. During gear shifting, as long as the wheel speed matches the engine speed, no additional braking is needed. However, be cautious with older cars. If the transmission fluid hasn't been changed for too long, the clutch plates might have delayed response, causing jerks when shifting without braking. I've encountered several customer cars where the solenoid valves were worn out, making loud noises when directly shifting to S gear. Well-maintained cars are completely fine, but for older cars with over 150,000 kilometers, it's always better to shift gently.

[McJulia]

The driving instructor didn't teach this detail at all last time! After figuring it out myself, I realized there's no need to press the brake. Once at a red light, I tried shifting directly from D to S, and the car remained stable. Now I use S gear for going up and down the garage, and shifting without braking is really smooth. However, with my dad's old Buick, you need to ease off the accelerator when shifting, otherwise the jerk is quite noticeable. Beginners are advised to practice a few times in the 40-60 km/h range to get a feel for the shifting timing. Remember, switching to S gear is especially useful for uphill driving in rain or snow, as it prevents wheel slippage.

[DelBrantley]

From a mechanical principle perspective, there's absolutely no need to press the brake. D mode and S mode belong to the same directional gear sequence, and modern vehicle TCUs are equipped with dynamic shift compensation functionality. I've tested this - when switching between these two modes at 60km/h, the transmission oil pressure synchronization completes within 0.2 seconds. However, three special scenarios require attention: gear shifts during continuous steep slope turns might trigger downshift protection; avoid shifting during the restart moment of vehicles with auto start-stop systems; remember to lock the transmission in tow mode. Actually, the dashboard is the most reliable indicator - as long as the engine warning light isn't yellow, feel free to switch as you please.

[IslaRose]

From a safe driving instructor's perspective: It's generally fine to switch gears directly during normal driving, but extra caution is needed in sudden situations. For example, suddenly shifting from D to S gear while climbing a hill in traffic may cause faster throttle response and increase the risk of rear-end collisions. Shifting gears abruptly when driving through waterlogged roads in rainy conditions may lead to sudden torque changes in the transmission, potentially causing the tail to swing out. I always emphasize three points to my students: check the rearview mirror before shifting gears, adjust the throttle depth with your right foot in advance, and avoid shifting during continuous curves. In fact, the manufacturer's manual clearly states on page 137 that 'driving modes can be freely switched while moving,' but for older CVT models, it's best to maintain a steady speed before shifting.