How long should a sedan be preheated?
2 Answers
Sedans only need about one minute of preheating. The reason for preheating is: After the car has been parked for a long time, the engine oil flows back to the oil pan at the bottom of the engine. When starting, the upper part of the engine lacks oil and lubrication. The purpose of preheating is to raise the temperature of the engine oil and improve its lubrication effect. The functions of preheating are: 1. Heating the antifreeze to improve the car's starting speed; 2. Maintaining the temperature of the engine block when the car is not in use, especially in low temperatures; 3. Preheating the engine oil to ensure it remains fluid for immediate circulation throughout the engine upon starting.
As a car owner who's always in a rush to get to work in the morning, I find that warming up the engine for about 30 seconds to a minute is usually sufficient, especially in summer when it really doesn't need much longer. In winter, it might extend slightly to one or two minutes, but anything beyond two minutes is excessive—modern engines are designed well, and idling for too long just wastes fuel and increases carbon buildup. The key is adjusting based on the temperature—on cold days, it's safer to wait until the RPM stabilizes before driving off. I've noticed that prolonged warm-ups often make the exhaust smell stronger, which isn't great for the environment either. Actually, the main purpose of warming up is to let the oil circulate evenly to protect engine components, and driving at low speed for a few minutes after starting is also a good method—it saves time and is efficient. I've been using this trick for years, and my car has run over 100,000 kilometers without major issues—it's a practical tip.
