Does running the air conditioner in P gear affect the car?

[DelCooper]

P gear, also known as the parking gear, can cause certain hazards to both people and the car when the air conditioner is left running for extended periods while parked. Below are some key points regarding the use of P gear: 1. Stationary gear engagement: The vehicle must come to a complete stop before shifting into P gear from any other gear; otherwise, it may damage the locking mechanism inside the transmission and the gear shift switch. 2. Engage the handbrake first: If parking on a slope, always engage the handbrake before shifting into P gear. 3. No towing: When in P gear, the drive shaft is mechanically locked, making towing impossible. 4. Manual release: If the vehicle cannot be shifted out of P gear, gently pushing the car back and forth slightly can help disengage the tightly interlocked parking pawl and output gear inside the transmission, allowing easy shifting from P gear to other gears.

[RiverLee]

I've been driving for ten years and often wait in the car with the AC on while in P gear. Honestly, doing this for short periods doesn't harm the car at all. The engine is designed to handle idling with load, and the compressor works perfectly fine. However, there are two things to note: First, don't do this in an enclosed space—idling with the AC on in a garage or underground parking lot is especially dangerous because exhaust fumes can't escape, leading to carbon monoxide poisoning. Second, if you idle for more than half an hour, carbon buildup will increase, and fuel consumption will rise. My personal experience is to wait under a tree in summer with the AC on and windows open—it's both cool and safe. Also, I'd like to remind new car owners to regularly check the battery condition. Frequently using the AC in P gear won't directly damage the battery, but it can add strain if the battery is already weak in an older car.

[FinleyDella]

As an environmentalist, let me discuss the energy consumption aspect of running the AC in P mode. When the AC is on while the vehicle is idling, the engine power utilization is very low, and the fuel consumption can skyrocket to over 3 liters per 100 kilometers, which is two to three times the normal driving consumption. The most critical issue is carbon buildup. Prolonged operation in this manner can coat the engine's throttle body and spark plugs with incompletely burned carbon particles, leading to reduced power. Through my experiments, I found that idling with the AC on for more than 10 hours per month results in noticeably sluggish acceleration after 5,000 kilometers. My recommendation is to turn off the engine if parked for more than 3 minutes—many modern cars come with auto start-stop features that perfectly address this issue. If you must run the AC, choose a well-ventilated area, leave the windows slightly open to reduce fuel consumption, and take the car on a high-speed drive once a month to help clear out carbon deposits.

[ChaseRose]

The mechanic reminds you that using air conditioning in P mode depends on two key factors: vehicle condition and duration. New cars can generally handle it without issues, but older models require caution. Engine carbon buildup can clog fuel lines, and the transmission may overheat, especially during idling for more than twenty minutes. I've dealt with numerous cases of damage caused by idling with AC on. The most severe was a 150,000 km SUV whose owner habitually napped in P mode with AC running, resulting in carbon deposits completely blocking the fuel injectors. Actually, many modern cars have improved designs, but for older vehicles, it's best not to exceed half an hour. Additionally, it's recommended to rev the engine slightly after starting the AC to reduce cold-start wear.