Composition of Lubricants

윤활유 구성도

※ The configuration of lubricants depends on type and viscosity of lubricants.

Types of base oil by API

Oil Division sulfur(%) Saturation degree(%) viscosoty index
Group 1 > 0.03 and/or < 90 80~120
Group 2 ≤ 0.03 and ≥ 90 80~120
Group 3 ≤ 0.03 and ≥ 90 ≥ 120
Group 4 PAO
Group 5 Other base oil except Group I, II, III, IV (Ester, PAG etc)
  • Group 1
  • · Features of Group I base oil: saturation degree is below 90%, sulfur is over 0.03%, and viscosity index is from 80 to 120. This base oil is .

    · produced through simple refinement of solvent and it is cheapest one among other base oils.

  • Group 2
  • · Features of Group II base oil: saturation degree is over 90%, sulfur is below 0.03%, and viscosity index is from 80 to 120. This base oil is.

    · produced through decomposition of hydrogen which is more complicated process than Group I base oil made. Group II base oil has more.

    · transparent color than Group I base oil but it is not expensive. That is why Group II base oil is popular in usage.

  • Group 3
  • · Features of Group III base oil: saturation degree is over 90%, sulfur is below 0.03%, and viscosity index is over 120. Group III base oil is.

    · produced through more refinement and severe decomposition of hydrogen process with higher temperature and pressure than Group II .

    · base oil.

    · Even though Group III base oil is produce from crude oil, it is sometimes called as synthetic base oil. Group III base oil is popular in usage like Group II.

  • Group 4
  • · Features of Group IV base oil: It is PAO(Poly Alpha Olefins). This synthetic base oil is produced though the process of synthesis. Group IV

    · base oil is best base oil which can be working well in wide range of temperature and especially in extremely low or high temperature.

  • Group 5
  • · Features of Group IV base oil: it does not belong to Group I~IV which includes Silicone, Phosphate ester, PolyAlkylene Glycol(PAG), Poly-

    · olester(POE), Biolube, etc. Group V base oil is used together with other base oil(Group I~IV) to improve performance of other base oil.

Types of additives

Division
Viscosity Modifier Keeping stable viscosity in high or low temperature.
Detergent & Dispersant Preventing sediment in the passage of lubricants and inside engine by catching contaminating materials and decomposing
Anti-Oxidant Increasing viscosity and reducing sludge and sediment by inhibiting the chain reaction of oxidization with oxygen, nitrogen, heat etc.
Anti-wear Preventing abrasion by friction between metals.
Pour Point Depressant Preventing frost of wax by eduction in low temperature.
Anti-foamer Preventing and decomposing foam in lubricants.
Friction Modifier Improving fuel efficiency by reducing friction.
Corrosion and Rust Inhibitor Preventing rust by acidic components arising from condensate moisture and incomplete combustion.