Should an automatic car be shifted to neutral when waiting at a red light?
3 Answers
It is recommended to shift to neutral when waiting at a red light in an automatic car, and you can also engage the handbrake if the wait is longer. Here is the relevant information: Consequences of shifting to N gear: When waiting at a red light, shifting to N gear for a short period is fine, but leaving it in N gear for an extended time can damage the car, especially the transmission. Reasons for shifting to neutral: Reduces wear on the car: When an automatic car is in D gear, even without pressing the accelerator, the car will slowly move forward due to the engagement of the transmission gears. In this case, you must press the brake to use the braking force of the brake pads to stop the car from moving forward. Lowers fuel consumption: When shifting to N gear during traffic jams or at red lights, the passive wheel in the torque converter of the transmission is in a freewheeling state, which does not increase the resistance of the active wheel connected to the engine. Without additional load, fuel consumption naturally does not increase.
When waiting at a red light with an automatic transmission car, I usually decide my operation based on the duration. For short red lights lasting 20-30 seconds, I simply press the brake and stay in D gear to avoid the hassle of switching back and forth. If encountering a long red light over 60 seconds, I definitely shift to neutral and engage the handbrake to give my right leg a complete rest. The transmission does produce slight vibrations when braking in D gear, especially noticeable in older models, and shifting to neutral reduces the load on the torque converter. Once on a rainy day, I forgot to engage the handbrake and the car rolled half a meter, so now I always confirm the handbrake indicator is lit during prolonged waits. Although modern cars are designed to withstand parking in D gear, keeping your foot from getting sore during half-hour traffic jams is what really matters.
I pass through seven traffic lights on my commute and have experimented with various operations. For short waits, keeping it in D gear is the most convenient—just step on the gas when the light turns green. For red lights lasting over 30 seconds, shifting to neutral and engaging the electronic parking brake allows my right foot to relax completely and significantly reduces lumbar pressure. Comparing the instant fuel consumption gauge, idling in neutral burns 0.2 liters less fuel per hour than holding the brake in D gear—it adds up over time. When I upgraded my lights and rims, the tuning shop owner mentioned that cars with auto start-stop don’t need to shift to neutral at all. Just remember to keep your foot on the brake pedal when in neutral, especially on slopes.
