
Automatic transmission gear sequence is P, R, N, D. The details are as follows: 1. P gear: Parking gear, which should logically be the first or last. 2. D gear: Drive gear, theoretically it could be placed anywhere, but currently most are manual-automatic integrated. After shifting to D gear, there are additional forward (up) or backward (down) or left-right operations for manual mode or S gear sport mode. Placing it in the middle is neither reasonable nor convenient, so the last position is more logical. 3. R gear: Reverse gear. If it is swapped with N gear (neutral), being adjacent makes it easy to mistakenly shift into drive gear, which can lead to traffic accidents or damage the transmission. Therefore, N gear is placed in the middle as a buffer, and it is also convenient to shift to neutral when stopping, such as waiting at a red light or for a brief stop. 4. N gear: Neutral gear, with reverse gear above and drive gear below, allowing easy shifting up and down.

I did some research on this when I was driving an automatic transmission car before. The gear sequence is basically arranged as P-R-N-D-S/L, with the P (Park) gear at the top, and the R (Reverse) gear for backing up. You must press the brake to shift gears, especially when moving out of P gear, which is very noticeable—this design is to prevent misoperation. The D (Drive) gear is the most commonly used forward gear, while gears like S (Sport) or L (Low) are for special road conditions, such as climbing steep slopes where L gear provides more power. Once, when driving a friend's car, I discovered there was also an M (Manual) gear for manual shifting, but for most daily driving, the D gear is completely sufficient. Automatic transmissions are easy to use, but not understanding these symbols can be quite dangerous.

When I first started with automatic transmissions, I also couldn't remember the gear sequence. Actually, just remember the 'PRND' pattern: P for Parking, R for Reverse, N for Neutral (like at red lights), and D for Drive. Some cars have additional numbers or letters after D, like my car's S for Sport mode and L for Low gear. I've used L gear on mountain roads, and it does provide better stability. The key is to develop the habit of checking the gear before starting – never mistake the accelerator for the brake. I've seen someone stomp on the accelerator in R gear and wreck the rear bumper completely.

Automatic transmission shift levers are designed with safety logic. For instance, switching between P (Park) and R (Reverse) requires pressing the unlock button to prevent accidental engagement of reverse gear while driving. This mechanism is technically called the shift lock mechanism, controlled by a solenoid valve. During my last maintenance visit, the technician mentioned that many people don't know they should engage the parking brake first before shifting to P when parking on slopes for extended periods. Directly shifting to P puts stress on the transmission pawl, leading to metal fatigue and eventual failure. Newer models now feature electronic rotary gear selectors. Although they eliminate physical lever movement, the operational logic still maintains the PRND sequence.


