What season is 15w40 engine oil suitable for?
3 Answers
15w40 engine oil is suitable for all seasons. The number before the 'w' represents the freezing point temperature. The freezing point temperature for 15w oil is -20 degrees Celsius. The number after the 'w' represents the kinematic viscosity of the oil at 100 degrees Celsius, with higher numbers indicating higher viscosity. Engine oil, also known as motor lubricant, is composed of base oil and additives. The base oil is the main component of lubricating oil, determining its basic properties, while additives compensate for and improve the shortcomings of the base oil's performance. The functions of engine oil include: 1. Reducing friction and high temperatures; 2. Cooling and lowering temperature; 3. Cleaning and purifying; 4. Damping and cushioning; 5. Preventing rust and corrosion.
I've been driving for over twenty years and have always used 15W40 engine oil. It's suitable for all seasons, especially performing best in spring and autumn when temperatures are mild, providing moderate oil fluidity for smooth engine starts and protection. Where I live, winter lows reach minus five degrees Celsius and summer highs exceed thirty degrees, yet this oil handles it effortlessly—cold starts in winter remain smooth, while it maintains lubrication and reduces wear under summer heat. However, a heads-up: if you're in frigid northern regions where winter temperatures frequently drop below minus fifteen degrees, consider switching to thinner 5W or 0W oil to prevent hard engine starts. Remember to regularly check your oil condition—don’t blindly change oils with seasons. Good habits make cars last longer. My previous car ran for a decade without major repairs, thanks in no small part to this oil.
As a car enthusiast, I have to say 15W40 is a practical multi-grade viscosity engine oil. The number 15W represents its low-temperature fluidity in winter - the lower the value, the better it starts in cold weather. The 40 indicates high-temperature viscosity that protects the engine against heat, generally suitable for environments between 0°C to 40°C. In other words, it's appropriate for most regions in China from spring to autumn, and can even be used in winter when temperatures aren't too cold. Don't worry about the technicalities - simply put, it's an all-season oil. Unless you're dealing with extreme temperatures (like needing thinner 5W oil for Harbin winters), it works fine even in Sanya summers. I recommend fellow drivers check their vehicle manuals for specifications while using a viscometer to regularly monitor oil health - this maintenance approach is more convenient than seasonal oil changes and extends engine life. I often help friends maintain their cars this way with consistently positive feedback.
