Is it harmful to start driving without warming up the car in winter?

[SabrinaMarie]

Starting the car without warming it up in winter is harmful. It takes 2 to 3 minutes to warm up the car in winter. The method to warm up the car is: after starting the vehicle, let it idle for 2 to 3 minutes to allow the engine coolant to reach the normal temperature before driving. The damage caused by not warming up the car includes: causing engine wear, as the engine oil settles at the bottom when the car is cold, leaving the engine internals in a state of dry friction. The benefits of warming up the car are: 1. After the car has been parked for a long time, the engine oil flows back into the oil pan, leaving the upper part lacking lubrication. Warming up the car helps lubricate these parts; 2. When the engine has not reached its operating temperature, the fuel system cannot effectively vaporize the gasoline completely due to the low temperature. Warming up the car can effectively improve efficiency; 3. It helps the transmission gear oil to lubricate the upper part of the transmission.

[OWeston]

The mechanic mentioned this to me during the last repair. It's really not good for the engine to rev the throttle directly without warming up the car in winter. When the engine is cold, the oil becomes as thick as syrup, causing direct hard friction between the piston rings and cylinder walls. I've seen several cars with 70,000 to 80,000 kilometers on them that developed fine scratches on the cylinder walls because of this habit. Especially in Northeast China where temperatures drop to -20 or -30 degrees Celsius, lower-grade engine oil can even turn into a paste. The safest practice is to wait until the tachometer drops below 1000 RPM after ignition, which usually takes about a minute or two. By the way, idling for too long isn't ideal either—it leads to carbon buildup and wastes fuel. Once the RPM stabilizes, you can slowly drive for two to three kilometers to let the water temperature rise.

[DiHailey]

Our fleet drivers all have this habit: before starting the car in winter, they must pop open the hood and check the dipstick. When temperatures drop below 5°C, engine oil loses more than half of its fluidity, and turbocharger bearings are most vulnerable to this kind of dry friction. Once, I drove onto the highway without properly warming up the engine, and as soon as the coolant temperature gauge reached the midpoint, I heard the valves rattling. Now I've learned better – the few seconds it takes to plug in my phone for charging are enough to observe the oil pressure light. If I'm in a hurry, starting the engine and fastening the seatbelt is sufficient for the idle to stabilize. At this point, driving slowly in first gear provides better protection than idling the car, and it also allows the transmission fluid to warm up simultaneously.

[LilahDella]

Veteran drivers often say you need to warm up the engine thoroughly during a cold start, but modern fuel-injected cars really don't require that much time. After running an auto repair shop for twenty years, I've seen too many cases of excessive warm-up leading to severe carbon buildup that required cylinder head removal for cleaning. The key is actually the coolant temperature sensor—most modern vehicles adjust the air-fuel mixture via ECU within 30 seconds after ignition. Friends in northern regions should note: below -15°C, a 90-second warm-up is ideal, just enough for the oil pump to circulate oil to the camshaft. Recently, a CR-V owner reported morning startup noises—diagnosis revealed it was hydraulic lifters starving for oil due to insufficient warm-up.