What is the correct usage of D and S gears?

[BryceLee]

In automatic transmission vehicles, both D gear and S gear are forward gears. D gear is used for normal driving, while S gear can be used for overtaking or acceleration. S gear provides greater horsepower and stronger power but also consumes more fuel, whereas D gear is more economical. Therefore, it is not recommended to use S gear during normal driving, especially at slow speeds. Below are detailed explanations: 1. D gear: D (driving) is the forward gear. When driving in this gear, the hydraulic system control device shifts gears according to the preset program, and the entire process operates based on the set logic. Simply press the accelerator. 2. S gear: S (sport) is the sport gear. When this gear is engaged, the hydraulic system can only connect to the first and second gears of the forward gears, and the automatic transmission can only shift automatically between these two gears, unable to engage higher gears. The upshift is delayed, resulting in naturally stronger power. There is a noticeable downshift phenomenon when switching from D gear to S gear. This forced downshift is intended to obtain greater output torque, making the car feel more 'powerful'.