Use lubricating oil of appropriate viscosity grade  

For gasoline engines, API SM/CF/GF-4, SL/CF/CF-3 grades of pure gasoline engine oils should be selected according to the use conditions; for diesel engines, API CI-4/SL, CH-4/ should be selected according to the mechanical load The selection of pure diesel engine oil of SL grade shall not be lower than the requirements stipulated by the engine manufacturer.