Can 20w40 engine oil be used in winter?
2 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.
