Which gear should an automatic transmission car be in when warming up?

[StRebecca]

When warming up an automatic transmission car, it should be placed in P (Park) gear because P gear provides sufficient safety by locking all four wheels of the car to prevent rolling. Additionally, the engine speed in P gear is relatively higher, allowing the car to warm up faster. The ultimate purpose of warming up a car is to quickly activate various internal fluids in a short period. To achieve this, you can choose to idle the vehicle in place. During idling, the engine rotates at a slower speed, allowing the fluids to be gradually activated by the engine. Since the piston movement is not particularly fast, it won't cause significant damage to the engine. The warm-up time should ideally be controlled between half a minute to one minute, after which you can start driving the car at a steady speed. In the past, warming up used to take three to five minutes before driving, which caused considerable damage to the car and also led to lower engine air intake, incomplete fuel combustion, and more carbon buildup.