The function of engine oil in automobile is to lubricate and cool the engine, and at the same time, it will remove carbon deposit, improve engine performance and prolong engine life. For cars with gasoline engines, it is necessary to use engine oil suitable for gasoline engines to ensure the normal operation of the engine system. Marking "gasoline engine oil" on the engine oil sign map is to distinguish other types of engine oil such as diesel engine oil and engine oil with different viscosity grades, so as to facilitate the owner to choose the appropriate engine oil brand, model and specification.

When selecting engine oil, it is necessary to select the appropriate engine oil according to the vehicle model and engine type. For example, diesel engines need to use engine oil suitable for diesel engines, with different performance and characteristics; At the same time, the influence of different viscosity grades should be considered in engine oil to prevent the engine from being too thick or too thin.