Can a National VI vehicle use regular fully synthetic engine oil?

[StLucille]

Manufacturers recommend using 0W-20 grade engine oil for vehicles meeting the National VI emission standards. For the Honda CB500X, either 10W-40 semi-synthetic or fully synthetic engine oil can be used. Engine oil viscosity labeling and meaning: Regardless of brand, engine oils use the unified SAE viscosity labeling system. Common viscosity grades include 5W-30, 10W-40, 15W-40, etc. The "W" stands for winter - the smaller the number before W, the lower the low-temperature viscosity, better cold flow performance, and lower applicable minimum temperature. The number after W represents the oil's high-temperature stability. Difference between fully synthetic and semi-synthetic oils: Fully synthetic oils offer better high/low temperature performance, longer oil change intervals, and are suitable for more severe operating conditions. Semi-synthetic oils contain more mineral oil, have higher pour points, and are more polluting to the environment.