At What Temperature Should You Warm Up Your Car?
2 Answers
Warming up your car depends on the specific temperature. Below -10°C, warm up for 1 minute; below -20°C, warm up for 2 minutes; and below -30°C, warm up for 3 minutes. Here are the specific reasons why warming up is necessary: Vehicle parked for a long time: After prolonged parking, the engine oil flows back into the oil pan at the bottom of the engine. Therefore, when starting the engine after a long period of inactivity (such as overnight), the upper part of the engine is without oil and lacks lubrication. It takes about 10 seconds after starting for the oil pump to circulate oil to the parts that need lubrication the most, such as the pistons, connecting rods, and crankshaft. However, even if you start driving immediately after starting the engine, as long as you don't accelerate aggressively and maintain low-speed operation, the effect is the same as idling. Low temperature of the fuel system: Before the engine reaches its operating temperature, the fuel system, due to its low temperature, cannot effectively vaporize the gasoline completely (as we all know, liquids vaporize when reaching their boiling point). When gasoline is not vaporized and remains in a "wet" liquid state, it is difficult to ignite and start the engine. At this point, the choke valve comes into play, restricting some air from entering the cylinders to increase the gasoline/air mixture ratio and raise the engine speed to prevent stalling. Once the normal operating temperature is reached, the automatic choke valve will naturally return to its normal state due to mechanical action. For cars with a manual choke valve, remember to reset it; otherwise, an overly rich fuel/air mixture will not only waste gasoline and reduce power but also cause incomplete combustion, resulting in black smoke. A cold engine takes about 7 to 10 minutes or more to reach normal operating temperature, depending on the vehicle type. During this period, there's no need to warm up the car while stationary; just avoid high-speed driving.
From my years of driving experience, warming up the car is quite necessary when the temperature drops below freezing, such as on winter mornings when a cold front arrives. After starting the engine, waiting for a minute or two to let it warm up before driving is not just a habit but also a way to protect the engine. Engine oil becomes more viscous in low temperatures, and pre-warming helps lubricate the components, reducing friction and wear. If you rush to drive on the highway without warming up, it may accelerate component aging and affect the car's lifespan. Therefore, it's best to warm up the car when temperatures are below freezing, but don't wait too long—just a few minutes is enough. Many modern cars come with a pre-heating function, so a brief wait after starting is sufficient.
