What Gear Should an Automatic Transmission Car Be in When Warming Up?
3 Answers
It is safer to warm up an automatic transmission car in P (Park) gear as this locks the tires. Warming up in N (Neutral) gear may cause the car to roll if the ground is uneven, even with the handbrake engaged. Below is an introduction to the gears of an automatic transmission car: 1. P (Parking): Engaging P gear after the car stops prevents movement through braking. Some models now feature an independent P gear, referred to as electronic braking. 2. R (Reverse): This gear can only be engaged when the vehicle is stationary for reversing. Models with a lock button require pressing the button to switch. 3. N (Neutral): Use this gear for temporary stops, such as at traffic lights, and always engage the handbrake. 4. S (Sport): The difference between D and S gears is simply the computer switching to different shifting programs, so S gear can be engaged at any time without adverse effects like damaging the transmission. 5. D (Drive): The most commonly used gear for driving forward, where gear changes are controlled by the accelerator. D1 (or L gear), D2, and D3 correspond to manual transmission gears 1 and 2, 3 and 4, and 5 and 6, respectively.
When warming up my automatic transmission car in winter, I always leave it in P gear, which is the parking gear, so the engine can focus on heating up without worrying about anything else. Right after starting, the engine temperature is low, and the engine oil is as thick as honey. Shifting directly to D gear would put extra strain on the engine. I usually start the car in the morning and wait for a minute or two in P gear until the tachometer needle drops from around 1200 RPM to about 800 RPM before driving off. Warming up the car while driving saves both time and fuel. Prolonged idling for warming up isn’t beneficial—it can lead to carbon buildup in the engine and harm the catalytic converter.
When warming up an automatic transmission car, I always recommend shifting to neutral or park. In neutral, the engine only needs to maintain its own operation, while in drive gear it requires additional effort to move the transmission load. After each cold start, I check the oil temperature gauge on the dashboard and wait for the needle to move from the blue zone to the normal position before driving. Warming up is essentially an oil temperature issue - it takes 1-3 minutes for the engine to reach operating temperature. Driving in gear during this period may accelerate wear on the hydraulic control unit. In extremely cold weather, I'll warm up a bit longer, but never more than three minutes.
