As the demand increases for high performance lubricants, the use of higher quality base oils becomes important.The American Petroleum Institute (API) classifies base oils using the following characteristics:

• Viscosity Index
• Saturate Level
• Sulfur Content

Base oils can have a direct effect upon the quality of finished lubricants, which makes them an important component in all lubricant formulations.

The five API categories for base oils are:
Group I - Viscosity index between 80 and 120, and less than 90% saturates and/or more than 0.03% sulfur.
Group II - Viscosity index between 80 and 120, and 90% saturates or greater and 0.03% sulfur or less.
Group III - Viscosity index of 120 or higher, and 90% saturates or greater and 0.03% sulfur or less.
Group IV - All polyalphaolefins (PAOs).
Group V - All other base stocks not included in Groups I through IV.

For more information, please contact our Technical Services Dept.