What is the impact of turning off the car directly in D gear?
3 Answers
Turning off the car directly in D gear does not have a significant impact on the vehicle. 1. The automatic start-stop system turns off the engine in D gear, but the key issue lies in how to restart the engine after turning it off in D gear—improper operation can damage the transmission. 2. If the engine is turned off in D gear while the car is parked, you can shift back to N or P gear; if the engine stalls while driving, you must shift to N gear to restart, as the engine cannot be restarted in D gear. Here is additional information: 1. Engine stalling, also known as shutdown, occurs when the reactor is operating at a significant reaction rate. If the inlet temperature is lowered to reach the lower limit of the multiple-state region, the reaction rate suddenly drops sharply, and the reaction essentially stops. 2. Gear shifting (changing gears) refers to the transmission, which is used to alter the torque and speed of the engine crankshaft to meet the varying requirements of driving wheel traction and speed under different driving conditions, such as starting, accelerating, driving, and overcoming various road obstacles.
Shutting down directly in D gear can lead to serious consequences. Having repaired cars for many years, I've seen numerous car owners face major troubles from this practice. When an automatic transmission is in D gear, it's in driving mode. After the engine shuts off, the gears continue rotating without power input, causing internal impacts and accelerating wear on gears and clutch plates. Over time, this can lead to transmission oil leaks or valve body failures, with repairs costing several thousand or even tens of thousands of yuan. More critically, if the car hasn't completely stopped, shutting off the engine will disable the brake booster system and make steering difficult, increasing accident risks. It's advisable to develop the habit of shifting to P or N gear before shutting off the engine to protect your transmission's lifespan and your own safety. Remember, small habits save little money, but damaging major components will cost you dearly.
As a veteran driver with over 20 years of experience, I've personally experienced the embarrassment of stalling directly in D gear. Once in a hurry to get out of the car, I forgot to shift gears and turned off the engine directly. The car immediately jerked, and when restarting, it was difficult to shift gears, almost failing to start. This subjects the transmission to unnecessary load, causes abnormal internal oil pressure, and accelerates component aging. It may also damage the starting system or electrical circuits. In terms of safety, if the vehicle is moving at the moment of stalling, power steering and brake assist disappear immediately, increasing the risk of losing control. I later learned my lesson and always carefully check the gear position after parking, ensuring to stall in P gear. Protecting the car is protecting yourself; don't cut corners and plant hidden dangers.
