Can 20w40 engine oil be used in winter?
4 Answers
Whether 20w40 engine oil can be used in winter depends on the temperature: it can be used when the temperature is above -15 degrees Celsius; it cannot be used when the temperature is below -15 degrees Celsius. The main functions of engine oil are: 1. Lubrication; 2. Auxiliary cooling; 3. Cleaning; 4. Sealing and leak prevention; 5. Rust and corrosion prevention; 6. Shock absorption; 7. Anti-wear. The method for adding engine oil to a car is: 1. Pull out the oil dipstick, wipe it clean, and measure again to see how much oil is missing; 2. Open the oil cap and add oil, then close the cap and start the engine for a few minutes to allow the oil to circulate in the engine, then check the oil dipstick again.
As a veteran driver with decades of experience, let me tell you whether 20w40 oil can be used in winter—it depends on how cold the weather gets. The 'W' in this oil stands for a winter viscosity grade of 20, which means it starts fine in above-freezing temperatures, like most winters in southern regions where it stays above freezing—no issues there. But when temperatures drop below -10°C in northern areas, the oil thickens too much, making engine starts difficult and potentially increasing wear. My advice? Don’t take the risk. Before winter, check your car’s recommended oil grade—the manual usually suggests 5w or 10w oils for better low-temperature flow. Choose oil suited to your local climate when changing it to avoid breakdowns. Regular maintenance is the way to go—keeping your engine healthy means a longer lifespan and less time wasted on repairs.
Be cautious when using 20W40 engine oil in winter. The low-temperature viscosity grade of this oil is 20W, meaning it maintains decent fluidity at temperatures around -20°C, but when it gets colder, such as during cold snaps, the oil film thickens, making engine startup difficult. I've seen many cases in car enthusiast circles where using the wrong oil leads to sluggish cold starts in winter, increasing fuel consumption and damaging the engine. Personally, I think if you live in an area where winter temperatures usually stay above freezing, 20W40 is perfectly usable; but in places with severe freezing, it's better to switch to a lower viscosity oil like 5W30. When seasons change, get your oil quality checked at a repair shop in advance—don't wait until your car breaks down. Safe driving is the top priority.
The usability of 20W40 oil in winter depends on specific temperatures. W20's low-temperature grade is sufficient for winter in mild climates, but when temperatures drop below -10°C, the oil thickens, increasing engine starting pressure and wear. In daily use, try to avoid prolonged driving in extremely cold weather. If your area frequently experiences freezing conditions, switching to 5W40 is safer as it offers better fluidity and component protection. Regular oil level checks are essential, and frequent oil changes can extend engine life.
