What Are The Characteristics Of Internal Combustion Engine Oil?
Engine oil low temperature (-5 ~-30 ° C) generally requires starting viscosity in the range of 6000 ~ 3000 mPa · s; oil at high temperature and high speed (100 ° C) can maintain the lowest kinematic viscosity of the oil film, generally not less than 3.8mm2 / s . Otherwise, the oil film is easily broken and the sealing effect is not good. The viscosity of the internal combustion engine oil should have a good high temperature and low temperature viscosity, that is, the viscosity is good. The viscosity-temperature properties of lubricating oils are expressed in terms of viscosity index (see lubricants). A high viscosity index indicates a small change in viscosity due to temperature changes. Generally, the viscosity index of single-stage oil is between 90 and 105, and the viscosity index of multi-grade oil is between 120 and 180.
2. Oxidation stability
Zinc dialkyl dithiophosphates and other antioxidants are generally used in oil formulations to improve the antioxidant properties of the oil.
3. Clean dispersion
On the one hand, it can inhibit the formation of oxidized jelly and coke, on the other hand, it can wash the sediment and suspend it in the oil, thereby reducing the tendency of the paint film and coke formation on the piston. The detergency of internal combustion engine oil is mainly achieved by adding additives such as calcium sulfonate (magnesium), sulfurized alkylphenol calcium, calcium hydrate and succinimide.
4. Anti-wear performance
That is, the ability of the lubricating oil to maintain a tight and strong oil film on the metal surface. Generally, an oily agent such as a sulfurized ester is added to improve the abrasion resistance of the oil.