Should I shift to P or N gear when waiting at a traffic light?
2 Answers
When waiting at a traffic light, shift to N gear and engage the handbrake. The N gear disconnects the engine from the transmission, and the passive wheel of the torque converter in the transmission is also in an idle state. At this time, it will not increase the resistance of the active wheel connected to the engine, and fuel injection will be reduced, making it relatively more fuel-efficient. However, to prevent the car from rolling, you must step on the brake or engage the handbrake. When the vehicle is shifted to P gear, the locking plate will engage the transmission gear, putting it in a mechanically locked state. If a rear-end collision occurs at this time, the transmission will be damaged, and severe impact may even cause the gear to break directly. Therefore, shifting to P gear is not advisable.
When waiting at a red light while driving, it's generally recommended to shift to Neutral (N) gear and engage the handbrake. Why? Although shifting to Park (P) gear locks the transmission and provides anti-roll safety, if a rear-end collision occurs, the impact force could severely damage critical internal components of the car. From a safety perspective, the N gear keeps the car in a neutral state, reducing unnecessary engine load, avoiding wear from frequent gear changes, and minimizing accident risks. Personally, I think using N gear for short stops at red lights during city commutes is the most reasonable approach, as it also slightly saves fuel. But remember, any operation must be accompanied by braking, otherwise the car may roll. I've maintained this habit for years, inspired by an experienced mechanic's advice: don't take shortcuts by shifting to P gear for brief stops. In short, adjust flexibly based on the length of the red light, but safety always comes first—choose N gear for red lights longer than 10 seconds.
