Synthetic oil is a lubricating oil prepared by chemical synthesis into higher molecular compounds and then blended or further processed. It includes synthetic esters, poly-α-olefins, polyethers, silicone oils, etc., and its composition is different from kerosene hydrocarbons. Semi-synthetic oil refers to lubricating oil made by mixing synthetic oil and mineral oil in a certain proportion. Because the raw materials of synthetic oil are expensive, the synthesis process is complicated, and the investment is high, the cost of synthetic oil and semi-synthetic oil is generally higher than that of mineral oil.
Compared with mineral lubricants, synthetic oil has the following excellent characteristics:
(1) Excellent viscosity temperature and low temperature fluidity
Synthetic motor oil has a higher viscosity index than mineral oil, and its viscosity changes with temperature. When the viscosity at high temperature is similar, most synthetic oils have a lower pour point (or freezing point) than mineral oils, and low viscosity at low temperatures. With the same oil film requirements, synthetic oil can be formed with a lower viscosity to protect the engine. At the same time, since the time required for the lubricating oil to flow to the friction surface is short, the dry wear of engine components can be reduced when starting and the service life of the engine can be extended.
(2) High temperature oxidation resistance
The thermal oxidation performance of synthetic oil is far better than that of mineral oil type oil, that is, the tendency to produce acidity and sludge due to oxidation is less. Under various harsh operating conditions, it can provide proper lubrication and effective protection to the engine, so it has Longer service life ensures the performance stability of the oil during long-term use.
In a similar working environment, synthetic oil has a much longer service life than mineral oil, so although it has a higher cost, it is not much higher than mineral oil after comparing the number of oil changes.
(3) Low evaporation loss
Synthetic oil is generally a pure compound with a narrow boiling point, and its evaporation loss is much lower than that of mineral oil, which can reduce fuel consumption, reduce exhaust emissions and extend the service life of catalytic converters.
Compared with traditional mineral oil-based oils, synthetic oils also have excellent chemical stability, good radiation resistance, high oil film strength and less foam.
Some problems arise when replacing a typical mineral oil type engine oil with a typical synthetic type oil. Ester, which is one of the base oil components of synthetic oil, has outstanding natural cleaning applications. It can clean the film formed in the engine due to thermal oxidation and decomposition when using mineral oil, and float on the surface of the lubricating oil. This surface material can clog the filter and block the oil circuit, resulting in insufficient oil supply. Therefore, when changing to synthetic oil for an engine that has used mineral oil for a period of time, you must pay attention: the lubrication system must be cleaned before the oil change, and the machine must be carefully checked before starting the machine.
