What is the Difference Between D Gear and S Gear in Automatic Transmission Cars?
2 Answers
The differences between D gear and S gear in automatic transmission cars include different main functions and characteristics. The specific introductions are as follows: Different Main Functions: S gear is the sports mode of the car; D gear is one of the most common gears in automatic transmission models, enabling the car to automatically select the appropriate gear while moving forward. Different Characteristics: When using S gear, due to the high rotation speed, the engine's fuel injection volume changes, increasing the power output. At the same time, the suspension becomes stiffer compared to normal conditions, reducing body roll during cornering. D gear is one of the most common gears in automatic transmission models, belonging to the forward gear category, covering all forward gears within the car's automatic transmission. Different Principles: In S gear sports mode, the transmission can shift freely, but the shifting timing is delayed, keeping the engine at high rotation speeds for a longer period. This allows the car to maintain a lower gear with higher rotation speeds for an extended time, resulting in greater torque output and acceleration. When the gear shift lever is placed in D gear, the hydraulic control system automatically connects the corresponding forward gear circuit based on the throttle opening signal and vehicle speed signal. As the output shaft speed and engine speed change, the transmission automatically shifts up or down to the appropriate gear within the forward gears, achieving the automatic transmission function.
As someone who frequently commutes in the city, I find a significant difference between the D gear and S gear in automatic transmission cars. Simply put, the D gear is the normal driving mode, providing a steady and smooth ride, ideal for daily traffic jams or highway driving, with smooth gear shifts, fuel efficiency, and quiet operation. The S gear, on the other hand, is the sport mode, offering faster and more aggressive acceleration, with noticeably more intense vehicle response, suitable for overtaking or climbing steep hills. I once used the S gear while driving on mountain roads and felt the RPM rise sharply, with power surging, but it consumed more fuel and puts greater strain on the engine over prolonged use. For daily commuting, I mainly stick to the D gear—it's both safe and economical. For new drivers, I recommend starting with the D gear to get familiar with driving before attempting the S gear, to avoid losing control and causing accidents.
