Should an automatic transmission car be started in Neutral (N) or Park (P)?
2 Answers
An automatic transmission car should be started in Park (P). After starting from P, briefly passing through Reverse (R) will not damage the transmission as long as you don't linger. From a transmission principle perspective, the gear lever doesn't directly change gears - its movement only generates a signal. The pre-programmed system then determines whether to shift gears. The Transmission Control Unit (TCU) can mitigate potentially harmful operations to some extent. How automatic transmissions work: Each gear has different gear ratios, similar to how small and large gear meshing produces different rotation speeds. Lower gear ratios are used for low-speed driving (output shaft speed lower than engine speed) to obtain greater driving force, while higher gear ratios are used for high-speed driving (output shaft speed higher than engine speed) to reduce traction and achieve higher speeds. Shifting essentially means selecting different sized gears to mesh with the output shaft gears.
When I first got my driver's license, I tried starting my friend's automatic transmission car in Neutral (N) gear, and the car almost rolled back on a slope, which gave me a scare. Later, I asked my driving instructor and learned that Park (P) gear is designed to lock the transmission, preventing the vehicle from moving. Starting in Neutral lacks this protection, and if the handbrake isn't fully engaged or the brakes fail, it can lead to accidents. Now, I always make it a habit to shift to P gear before starting the car—it's much safer and ensures a smoother ignition. By the way, developing this habit also helps prolong the transmission's lifespan and reduces wear. Although automatic transmissions are simpler to operate, paying attention to these small details is crucial, especially for beginners, to avoid potential hazards.
