What's the difference between automobile oil and heavy vehicle oil?

The difference between automobile oil and heavy vehicle oil is also the difference between gasoline engine oil and diesel engine oil. Automobile engine oil (hereinafter referred to as automobile engine oil) has low kinematic viscosity and good fluidity. Heavy-duty vehicles (hereinafter referred to as diesel engine oil) have high viscosity and stronger compression resistance. The working speed of gasoline engine is much higher than that of diesel engine, even double. Because of the high speed of gasoline engine, more engine oil is needed to lubricate, clean and dissipate heat of crankshaft and camshaft, so its kinematic viscosity should not be too large, otherwise it will affect the flow. However, the speed of diesel engine is low, but the compression ratio of diesel engine is higher and the crankshaft bears more torque. Therefore, the oil needs higher pressure resistance and higher pressure to be supplied to the crankshaft to ensure the formation of an oil film between the crankshaft and the bearing bushing. This is part of the difference between the two oils.