Search  
Login  | 
General Description of Base Oils

General Description of Base Oil

In 1990 API established a base oil classification system to help marketers to minimize re-testing costs when blending licensed engine oils with base oils from different manufacturing sources. The system uses physical and chemical parameters to divide all base stocks into 5 groups as listed below:

API - Classification of Base Oils

 

Group

Saturate wt %

Sulphur wt %

Viscosity Index

 

I

< 90 and / or

>  0.03

>  80 to <120

Paraffinic

II

>90 and

< 0.03

>  80 to <120

Paraffinic

III

>90

>  0.03

> 120

Paraffinic

IV

All poly Alpha Olefins (PAOs)

Lubricants property improves

V

All Base Stocks not incl. in Groups I- IV

Naphthenic – Synthetic esters

 

Paraffinic

High Viscosity Index

 

 

Better Oxidation stability – Low oxidation

 

 

Lower Volatility

 

 

Pour (freezing) Point is not very good – 20c

 

 

Solvency characteristics (additive mixing) are not good

 

 

Good to make engine Oils

 

 

Naphthenic

Low viscosity index

 

 

Bad oxidation stability – high oxidation

 

 

Higher volatility

 

 

Pour (freezing)points is very good – 60c

 

 

Solvency characteristics (additive mixing) are good

 

 

Good to make out of engine oils – e.g hydraulic etc.

 


Back

 
Copyright © 2011 - 2017 Chicago Group. All Rights Reserved. Terms Of Use  |  Privacy Statement