
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.

Over the years of driving automatic transmissions, I've figured out a pattern: for red lights under 30 seconds, stay in D gear; beyond that, shift to neutral and engage the handbrake. This protects the torque converter in the transmission and prevents brake light overheating. I once saw a test video showing that transmission oil temperature rises by about 5 degrees when braking in D gear, becoming more noticeable after ten consecutive stops. I've specifically noticed that shifting to neutral with the AC on makes the engine sound quieter. Always use the handbrake on slopes—I once saw a car roll back and hit a guardrail, which was a good lesson. Although new cars are designed to handle parking in D gear, keeping your right foot relaxed is most important.

I used to struggle with this as a beginner, but now I operate based on the duration of red lights. For lights under 20 seconds, I simply keep it in D gear and step on the brake. For longer red lights, I shift to N gear and engage the handbrake, so my right foot doesn't have to keep pressing. A mechanic friend mentioned that frequent gear shifts might wear out the gear lever mechanism, but keeping it in gear for over forty seconds can cause the transmission oil temperature to rise. Cars with auto-hold function are the most hassle-free, as they automatically apply the brake after stopping. Remember to firmly press the brake when shifting to neutral, otherwise there's a risk of the car rolling, especially on wet and slippery roads during rainy days. Older models tend to vibrate more when parked in D gear, shifting to neutral provides a smoother experience.


