Physical and chemical properties of truck lubricating oil/grease

Physical and chemical properties of truck lubricating oil/grease

Appearance (chromaticity)

The color of an oil product often reflects its degree of refinement and stability. For base oil, the higher the refining degree, the cleaner the removal of hydrocarbon oxides and sulfides, and the lighter the color. However, even if the refining conditions are the same, the color and transparency of the base oil produced from different oil sources and base oils may also be different.

For new finished lubricating oils, due to the use of additives, color has lost its original significance as an indicator of the degree of refining of the base oil.

density

Density is the simplest and most commonly used physical performance indicator of lubricating oil. The density of lubricating oil increases with the increase of the amount of carbon, oxygen, and sulfur in its composition. Therefore, under the same viscosity or relative molecular weight, lubricating oil with more aromatic hydrocarbons, more gum and asphaltene has the highest density, with more cycloalkanes in the middle and more alkanes in the minimum.

viscosity

Viscosity reflects the internal friction force of an oil product and is an indicator of its oiliness and fluidity. Without adding any functional additives, the higher the viscosity, the higher the oil film strength, and the worse the fluidity.

viscosity index

The viscosity index represents the degree to which the viscosity of an oil product changes with temperature. The higher the viscosity index, the less affected the temperature on the viscosity of the oil, and the better its viscosity temperature performance. Conversely, the worse the viscosity temperature performance.