What does D123 in automatic transmission mean?
2 Answers
D gear is the normal forward gear of the car, and 123 refers to the low gear mode of the transmission. Here is a detailed introduction to the D123 in automatic transmission: D1 gear: D1 gear is the heavy-duty gear. The transmission stays in first gear. D2 gear: The vehicle starts in D2 gear. The transmission stays in second gear, used for starting on slippery surfaces or as a limiting gear when moving slowly forward, avoiding gear shifts between 1st and 2nd, and 2nd and 3rd gears. D3 gear: D3 gear is the overtaking gear. It can be used as a limiting gear when traffic is not smooth, avoiding gear shifts between 3rd and 4th gears.
Seeing numbers like D123 on an automatic transmission can indeed pique curiosity. Having driven for over a decade, I most commonly use them for speed control during long descents. For example, when navigating mountain switchbacks, shifting to D3 locks the car in third gear, utilizing engine braking to reduce brake pedal usage and prevent brake pad overheating failure. During slow-moving traffic jams, switching to D2 makes for smoother driving, otherwise the transmission constantly shifts between 1st and 2nd gear, creating jerky movements like riding a horse. Recently when driving a friend's SUV up a steep slope, using D1 provided exceptional stability with no tire slippage whatsoever. Note that these gears aren't meant for racing—they're primarily for handling special road conditions and protecting the transmission. Remember to press the shift lock when changing gears; you can simply push the lever while driving without braking (a common question from beginners).
