Should Automatic Transmission Cars Shift to Neutral at Traffic Lights?

[SanCollin]

Automatic transmission cars should shift to neutral at traffic lights, and using the handbrake will be safer. Shifting to N (neutral) and applying the handbrake can save some fuel because the passive wheel in the torque converter of the transmission is in an idling state at this time, which does not increase the engine's operating load, thereby reducing fuel consumption. It is not recommended to use P (park) at traffic lights because shifting from P to D (drive) can easily cause a reverse movement, which may affect the vehicle behind and, in severe cases, lead to a rear-end collision. Of course, the driver would also bear some responsibility. Using D (drive) with the foot brake at traffic lights is also not ideal, as the passive wheel in the torque converter between the engine and transmission is fixed, creating a counterforce that acts on the driving wheel, increasing the engine's load. This can be understood as hindering the engine's operation, causing the engine ECU to increase fuel injection, leading to higher fuel consumption.

[AugustMarie]

I always drive an automatic transmission car, and when encountering a traffic light, I keep it in D gear and step on the brake. This is the most convenient and quickest way. As soon as the light turns green, I can go without needing to shift gears again, putting safety first to avoid rear-end collisions. In the city, red lights are short, and frequently shifting to N gear is tiring and prone to operational errors. Although shifting to N gear can save a little fuel and reduce engine load, modern car transmissions are very durable, and short-term idling in D gear is fine. I think keeping it in D gear is the most worry-free habit, especially for beginners who might panic easily—focusing on the road is more important. Never shift to P gear while waiting at a light; if rear-ended, it could damage the transmission. Overall, balancing safety and efficiency is key—don't take risks just to save a little fuel.

[VonEmmanuel]

Shifting to N gear at red lights does save a bit on fuel costs, and I often do this, especially when the red light lasts over half a minute. After switching to N gear, the engine idles with reduced load, leading to slightly lower fuel consumption, which is more noticeable when the air conditioning is on. Don't underestimate this; it can save you a few bucks on fuel each month. However, be cautious not to shift gears too frequently, as constantly switching between N and D gears may wear out the transmission, which isn't worth it. For safety, remember to engage the handbrake to prevent rolling, and keep an eye on the intersection to be ready to move when the light changes. I think the economic benefits are worth considering, but only switch during long red lights. For short red lights or heavy traffic, it's more reliable to stay in D gear and keep your foot on the brake.

[DiMichael]

From a mechanical maintenance perspective, keeping the car in D gear at red lights may increase transmission load. As someone who has repaired cars, I know the engine and brakes work against each other in this situation, causing slight clutch wear that can affect longevity over time. Shifting to N gear allows the engine to idle, better protecting components. However, modern automatic transmissions are robustly designed, so occasional D gear idling isn't a major issue. The key is not to overthink it - stay in D for short red lights; if exceeding one minute, shifting to N is more ideal. Ensure smooth gear changes to avoid jamming. Never compromise safety - always confirm the vehicle is stable before releasing the foot brake when shifting to N. The sweet spot is whatever feels most comfortable for you.

[AlinaFitz]

Using N gear at red lights is particularly practical for me, especially during long drives when my feet tend to get tired. After shifting to neutral and pulling the handbrake, my feet can relax and rest for a while. Switching back to D gear before starting is also quick. It's quite safe as long as you pay attention to your surroundings and don't fall behind. The operation is simple with just one-button switching, making it easy even for beginners to learn. I usually shift to N gear at long red lights in the suburbs, which saves effort and relieves fatigue; but in the city with short lights, I stay in D gear to remain alert. The comfort improvement is significant, avoiding foot fatigue from prolonged brake pressing. There's also a slight fuel saving, though that's not the main point. The key is finding what works best for you to make driving more enjoyable.

[DeHadley]

Most people driving automatic cars tend to keep the gear in D and step on the brake when waiting at red lights, and I used to do the same. Experienced drivers say that keeping it in D is the standard practice, as it allows for quicker starts and higher safety. Although shifting to N can save fuel or provide some relaxation, it’s more cumbersome to operate, especially in traffic jams where constant switching wastes time. Experts explain that vehicles are designed with D-gear standby optimization, so short stops won’t harm the car. Keeping it in D for short red lights is fine, but consider shifting to N for long waits—though don’t force it. My experience is that keeping things simple never goes wrong—it’s worry-free and effortless. New drivers should first master the basics—safety always comes first.