What Type of Engine Oil Should Be Used in Summer?

[StellaFitz]

In summer, 10W40 or 10W30 engine oil is generally recommended, as the oil type is clearly labeled on the bottle. When using your vehicle in summer, ensure proper lubrication while selecting engine oil with the lowest possible viscosity based on the temperature range, engine temperature, and actual vehicle condition. For engines in good condition with minimal wear, a lower viscosity oil is suitable. For engines with significant wear and larger clearances, a slightly higher viscosity oil may be appropriate. Engine oil, also known as motor lubricant, serves multiple functions including lubrication and wear reduction, auxiliary cooling, sealing against leaks, rust and corrosion prevention, and shock absorption.

[MacEthan]

I've been driving for over a decade, and choosing engine oil in summer requires attention to viscosity parameters. The smaller the number before the W, the better the low-temperature fluidity; the larger the number after, the stronger the high-temperature protection. In high-temperature regions like the south, higher viscosity oils such as 10W-40 or 15W-50 are more suitable, as they provide more stable oil films when the engine is hot. However, if the new car manual recommends 5W-30, don't arbitrarily switch to higher viscosity oils, as this can increase fuel consumption. Recently, I switched to full synthetic oil and found it more reliable—even during long-distance drives, the oil temperature remains stable around 110°C, and the engine sounds smoother. Remember to also check the coolant, as engine cooling systems face greater pressure in summer, and the oil cooling system must keep up.

[Clyde]

Many people mistakenly believe that they must switch to ultra-viscous oil in summer, but it actually depends on the vehicle's condition. Last month during my SUV's maintenance, the mechanic mentioned that with modern full-synthetic technology being mature, 5W-30 oil can still handle 35°C heat—the key is to check the high-temperature shear value in the ACEA standards. My car uses A5/B5 certified oil, and after a highway run, the dipstick showed the oil remained clear and didn't thin out. Of course, older cars are a different story—like my neighbor's 200,000 km Jetta, which only avoids burning oil in summer with 15W-50. Suddenly remembered tire pressure also needs adjustment in hot weather, as heat can cause overinflation, working hand-in-hand with the lubrication system.

[GrantAnn]

Last week while helping my cousin choose summer engine oil, I noticed several key points: First, check the owner's manual requirements - Japanese cars generally use 0W-20 while German cars prefer 5W-40. Second, consider local temperatures - above 35°C it's recommended to increase viscosity grade. For his Corolla in Hainan, I suggested switching to 5W-30 SP grade full synthetic with more high-temperature anti-wear additives. I also taught him a trick: ask the mechanic to clean the oil pan during oil changes as summer heat makes sludge buildup more likely. By the way, using AC increases engine load and accelerates oil degradation, so it's better to shorten the maintenance interval by 500 kilometers.