When to Replace Winter Engine Oil?
3 Answers
There is no need to specifically replace winter engine oil; you can simply change to new oil based on usage conditions. When a car frequently travels long distances, conventional oil needs to be replaced every 5,000 kilometers; semi-synthetic oil should be replaced every 7,500 to 10,000 kilometers; if the car uses full synthetic oil, it can be replaced every 10,000 to 15,000 kilometers. Engine oil, motor oil, or engine lubricant is a substance enhanced with additives in base oil, primarily containing anti-wear additives, detergents, dispersants, and multi-grade viscosity index improvers. Engine oil is used for lubricating internal combustion engines, with its main functions being to reduce friction and wear on moving parts and to remove sludge and varnish from the engine.
I've been driving for thirty years, and experience has taught me that the best time to replace winter engine oil is when temperatures consistently rise in spring. For example, in our area, by late March or early April, when local temperatures remain above freezing with no risk of frost, it's time to take care of it. Winter engine oil is thinner, specifically designed for cold starts. When temperatures rise, the oil film becomes thinner, reducing engine protection. Delaying the change can lead to increased friction and even abnormal wear. I remember one time I waited until May, and the engine made unusually loud noises. Upon inspection, slight internal abrasions were found—fortunately, I changed it early. Now, every year in early spring, I check the dipstick, observe the oil's color and viscosity, and if there are no impurities, I proceed with the change. Switching to seasonal oil types, such as from 0W-20 back to 5W-30, makes the engine run much smoother.
From the perspective of engine oil performance, winter-grade oils like 0W are designed for low-temperature environments, with lower viscosity facilitating cold-start flow. When temperatures rise above 10 degrees Celsius, it's time to switch to summer or multi-viscosity oils such as 5W-40 or 10W-30. Continuing to use winter oil in warmer weather can lead to insufficient lubrication due to overly thin oil, accelerating engine component wear and potentially increasing fuel consumption. I typically replace it when the daily average temperature exceeds 10 degrees, referring to the vehicle manual or consulting a professional technician to ensure compatibility. Here's a handy tip: keep a thermometer to monitor outdoor temperature changes. Opting for full synthetic oil can extend maintenance intervals, but don't cut corners when switching between seasons.
