Can different brands of lubricants be mixed?
Some maintenance factory managers or drivers think from the perspective of cost saving, in the season maintenance, they are reluctant to replace the remaining lubricant in the engine, and then add a certain amount of new oil to continue to use, sometimes simply two different The grades of lubricants are used in combination. This kind of approach seems to be no problem for the time being, but in the long run, it accelerates the wear and deterioration of the parts, and the cost increases. Different grades of lubricants cannot be mixed. For example, gasoline engine oil and diesel engine oil cannot be mixed. Normal oil and supercharged oil cannot be mixed. Single viscosity and multi-viscosity gear oil cannot be mixed. because:
(1) When designing, the automobile manufacturer shall specify the grade, oil change period and quantity of the lubricant to be used according to the structural characteristics of the vehicle, the ambient temperature and the conditions of use.
(2) The brands of the two oils are exactly the same as the varieties and viscosity grades, but the chemical components used in the lubricants produced by different manufacturers are not necessarily identical, and the lubricants blended with different chemicals are mixed together. After that, chemical precipitation occurs between the additive and the additive, and the effects cancel each other out.
(3) The lubricating oils of different grades have different physical and chemical properties, such as chemical composition, viscosity, acid value and various additives (anti-wear agents, preservatives, antioxidants, rust inhibitors) and other main components and indicators. It directly affects the operation of the machine and is prone to chemical reactions. When the engine is running, it is more reactive at high temperatures. If mixed, its performance will change, the operating temperature of the parts will increase, and a lot of bubbles will be generated and even deteriorate. The working conditions of the precision parts, running parts and seals of the automobile are also changed, the performance is lowered, the wear of the parts is accelerated, the seals are deteriorated, the seal is not good, and the lubricating oil is lost.
The engine lubricating oil is divided into two parts: the base oil and the additive. The base oil is further divided into Class I, Class II, Class III, Class IV, etc. The additive is further divided into an additive that changes physical properties and an additive that changes chemical properties. Such as viscosity index improver, defoamer, anti-corrosion rust inhibitor, anti-wear agent, antioxidant, detergent dispersant, etc.; from the performance of the engine oil is divided into four-stroke diesel engine oil, four-stroke turbine oil, diesel engine oil, Dual fuel engine oil, two-stroke diesel engine oil and two-stroke turbine oil.
Therefore, when replacing the lubricating oil, the old lubricating oil in the fuel tank should be drained. It is better to flush the system with new lubricating oil and then inject new oil.