Which gear should an automatic transmission car be in for prolonged idling?

[JulianAnn]

For prolonged idling of an automatic transmission car, it should be placed in P (Park) gear. What is P gear: P gear is a special parking position that mechanically locks the transmission output shaft to secure the vehicle. Its function is to act as a parking brake, preventing the vehicle from moving. Parking precautions: From a practical safety perspective, automobile manufacturers position P gear at the first spot on the gearshift console and implement an internal mechanism that only allows the car key to be removed when the gearshift lever is moved to P position. Therefore, P gear is specifically designed for prolonged parking in automatic transmission vehicles. When waiting in a parked car, try to avoid prolonged idling and consider turning off the engine instead.

[DelKhloe]

As an experienced driver who has been driving for many years, I think this issue is very important. For automatic transmission vehicles during prolonged idling, such as waiting at red lights, traffic jams, or long waits for someone, the safest practice is to shift into P (Park) gear. This is because P gear locks the transmission, preventing the car from moving unexpectedly, such as accidentally releasing the brake or rolling on a slope. Some people might be used to shifting into N (Neutral) gear, which works but isn't as safe as P gear and can easily lead to accidents. Shifting into D (Drive) gear should absolutely be avoided, as it keeps the engine and transmission in working condition for a long time, leading to overheating, increased fuel consumption, and even damage to internal components. I remember once idling in D gear for half an hour, and the transmission temperature skyrocketed, costing me a lot in repairs. So, for safety and vehicle protection, developing the habit of shifting into P gear when stopping is simple and practical.

[VonCatherine]

My experience as an instructor at a driving school has taught me that safety is paramount. When idling an automatic transmission vehicle for an extended period, it's essential to shift into P (Park) to ensure the vehicle remains completely stationary. Engaging P mode locks the drive wheels, effectively preventing rolling or accidental movement—a critical consideration especially for novice drivers. While shifting to N (Neutral) is technically possible, it offers no additional locking mechanism, posing significant risks if parked on an incline or near obstacles. Keeping the gear in D (Drive) is even worse, as it increases transmission pressure, leading to overheating and wear, plus unnecessary fuel consumption. Traffic regulations also remind drivers: shifting to P mode during stationary waiting is the best practice—not only preventing accidents but also extending vehicle lifespan. During daily instruction, I emphasize this point repeatedly—never cut corners by overlooking it. Cultivate the good habit: after coming to a full stop, press the brake and shift to P mode for total security.

[EmilianoLynn]

From an environmental perspective, we should reduce unnecessary idling time. For automatic transmission vehicles, if idling is unavoidable, shifting to P (Park) or turning off the engine directly is better. Shifting to P ensures vehicle safety, while shifting to N (Neutral) is also possible but not ideal—the main issue is that idling itself wastes fuel and produces more exhaust emissions. In urban pollution, vehicle idling accounts for a significant portion. If possible, turn off the engine; if not, shift to P to reduce energy consumption. Avoid keeping the car in D (Drive), as it increases fuel consumption and noise, which is harmful to both health and the environment. I often encourage everyone to minimize idling—when waiting or stuck in traffic, shifting to P saves more fuel.