Editing Lubricant (section)

=== Mineral oil ===

The term "[[mineral oil]]" is used to refer to lubricating base oils derived from [[crude oil]]. The [[American Petroleum Institute]] (API) designates several types of lubricant base oil:<ref>{{Cite web |url=http://www.api.org/certifications/engineoil/pubs/index.cfm |title=Engine Oil Publications |access-date=30 August 2007 |archive-date=1 July 2010 |archive-url=https://web.archive.org/web/20100701174323/http://www.api.org/certifications/engineoil/pubs/index.cfm |url-status=live }}</ref>

* Group I – Saturates < 90% and/or [[sulfur]] > 0.03%, and [[Society of Automotive Engineers]] (SAE) [[viscosity index]] (VI) of 80 to 120
: Manufactured by solvent extraction, solvent or catalytic dewaxing, and hydro-finishing processes. Common Group I base oil are 150SN (solvent neutral), 500SN, and 150BS (brightstock)
* Group II – Saturates > 90% and sulfur < 0.03%, and SAE viscosity index of 80 to 120
: Manufactured by hydrocracking and solvent or catalytic dewaxing processes. Group II base oil has superior anti-oxidation properties since virtually all hydrocarbon molecules are saturated. It has water-white color.
* Group III – Saturates > 90%, sulfur < 0.03%, and SAE viscosity index over 120
: Manufactured by special processes such as isohydromerization. Can be manufactured from base oil or slax wax from dewaxing process.
* Group IV – [[Polyalphaolefins]] (PAO)
* Group V – All others not included above, such as naphthenics, polyalkylene glycols (PAG), and [[polyester]]s.

The lubricant industry commonly extends this group terminology to include:
* Group I+ with a [[viscosity index]] of 103–108
* Group II+ with a viscosity index of 113–119
* Group III+ with a viscosity index of at least 140

Can also be classified into three categories depending on the prevailing compositions:
* Paraffinic
* Naphthenic
* Aromatic