What is Base oil
Base oils are not end products but as the name suggests, it’s the base input oil product used in manufacturing of lubricants such as gear Oil, motor Oil, hydraulic oil, greases and other lubricants for consumer and commercial purposes. Base Oils are produced from refining crude oil or through chemical synthesis in the case of synthetic base oil.
Base oil is also defined as oil with boiling point range between 550 and 1050 F, consisting of hydrocarbons with 18 to 40 carbon atoms. Base oils can be either paraffinic or naphthenic in nature depending on the chemical structure of the molecules.
GROUPS OF BASE OILS
There are about 5 Categories of base oils, based on certain chemical and physical properties. American Petroleum Institute (API) Specification 1509 determines the quality of base oil and also grouped base oil in to these 5 groups, Group I, Group II, Group III, Group IV and Group V. Base oil is priced based on the API category it meets.
Group I base stocks contain less than 90 percent saturates and/or greater than .03 percent sulfur and have viscosity index greater than or equal to 80 and less than 120.
Group II base stocks contain greater than or equal to 90 percent saturates and less than or equal to .03 percent sulfur and have viscosity index greater than or equal to 80 and less than 120.
Group III base stocks contain greater than or equal to 90 percent saturates and less than or equal to .03 percent sulfur and have viscosity index greater than or equal to 120.
Group IV base stocks are polyalphaolefins (PAO).
Group V base stocks include all other base stocks not included in Group I, II, III, IV.
The vast majority of oil falls into either Group I or Group II, with the higher group numbers (Groups III, IV, and V) being reserved for synthetic and semi-synthetic oil types.