Can a new car use 0w40 engine oil?
4 Answers
New cars cannot use 0w40 engine oil. New cars require higher viscosity, and using 0W40 will result in insufficient lubrication and accelerate wear on components. Suitable engine oil for new cars: If a new car only requires 0W20 viscosity engine oil, using 0W40 will cause some issues. Since the gaps between components in the engine of such cars are smaller, using 0W40 will increase engine resistance, leading to insufficient power and increased fuel consumption, among other effects. If the owner's car previously used lower viscosity engine oil, when the car reaches a certain age and becomes older, they may consider using 40 viscosity grade engine oil. Meaning of engine oil grades: For example, in 0W40, W stands for Winter, and the preceding number indicates low-temperature fluidity. The smaller the number, the greater the low-temperature fluidity, and it also represents the applicable minimum temperature. 0W is suitable for temperatures above -35°C; 5W is suitable for temperatures above -30°C; 10W is suitable for temperatures above -25°C, and so on.
Actually, I also pondered about engine oil when buying my car. The internal components of a new car's engine fit tightly together, making low-viscosity oil with better fluidity more suitable—just like using specialized lubricant for precision instruments. Although 0W40 has good low-temperature fluidity (the 0W means it can start even at -35°C), the high-temperature viscosity of 40 is a bit too high for a new car. The original manual usually recommends low-viscosity oils like 0W20 or 5W30, whereas using 40 viscosity would increase fuel consumption and slow down throttle response. For the first two years, my new car always used 0W20, and the engine sounded exceptionally smooth on the highway, with fuel consumption staying around 6 liters. If you live in a consistently hot place like Hainan, 5W30 might be more suitable. If you really want to use 0W40, I’d suggest waiting until the car has run over 50,000 kilometers before considering it.
I recently researched this while helping my cousin pick engine oil for his new car. Brand-new cars really don't need 0W40 - this viscosity is more suitable for older engines or performance vehicles that frequently run at high RPMs. Regular family cars have smaller engine clearances, and using high-viscosity oil actually increases moving part resistance, like running in a thick winter coat. I've checked over a dozen vehicle manuals - German cars might allow 40 viscosity, but Japanese/Korean models almost universally recommend 20 or 30. The technician during my last service mentioned that using excessively thick oil in new cars might even void the engine warranty. Of course, 0W's cold-weather performance is advantageous in -30°C Northeastern winters, but it's best paired with 20 or 30 viscosity. The key is checking the certification standard marked on the fuel cap or in the manual.
Choosing engine oil depends on the specific vehicle model. Last year, I bought a turbocharged car, and the 4S dealership clearly stated that 0W20 must be used, as using 40 viscosity might affect the variable valve system. The cold-start performance of 0W40 is indeed strong, capable of quick pumping even in sub-zero temperatures, but the high-temperature protection of 40 viscosity is somewhat excessive. New cars have smaller piston ring and cylinder wall clearances, and the thick oil film formed by high-viscosity oil not only increases fuel consumption but also affects heat dissipation. A colleague once mistakenly used 40 viscosity oil in their SUV, and the urban fuel consumption immediately rose by over 1 liter. However, vehicles equipped with particulate filters need to pay special attention to oil certification, as using the wrong oil may cause blockages. The simplest method is to check the maintenance manual—the viscosity range specified there is the most reliable.
