In daily applications, the description materials of some old machinery and equipment indicate the use of oil lubrication. The oil indicated in the old machinery and equipment is actually not the conventional internal combustion engine oil currently used, but the mechanical lubricant. Most of these old machinery Equipment lubrication has been replaced by hydraulic oil, but some processing plants will also use internal combustion engine oil for lubrication.

Internal combustion engine oil is a lubricating oil specially used for gasoline engines and diesel engines manufactured according to engine standards. The standard has a variety of performance indicators such as high detergency and dispersion.

Hydraulic oil is mainly used in various hydraulic oil systems. Its viscosity level is confirmed by the use of the hydraulic system. The additives used include anti-oxidation, anti-rust, anti-wear additives, which are completely different from internal combustion engine oils. Generally, hydraulic oil cannot be used as internal combustion engine oil because of its lack of detergency. However, in order to simplify the types of oil used on site, internal combustion engine oil (with suitable viscosity) can also be used as hydraulic oil in some cases. However, its performance parameters such as demulsification, hydrolysis stability, etc. cannot meet the requirements of hydraulic oil specifications. Therefore, in underground, offshore, and wet and cold natural environments, internal combustion engine oil must not be used to replace hydraulic oil.