http://www.msds.exxonmobil.com/psims/psims.aspx
Select Korea, English, and search for esp 5W-30.
Base Oil 1 below is Group III.
Name CAS # Concentration
Base Oil 1 92062-09-4 30-40%
Trade Secret 01 Trade Secret 20-30%
Trade Secret 02 Trade Secret 10-20%
Trade Secret 03 Trade Secret 5-10%
Trade Secret 04 Trade Secret 5-10%
Trade Secret 05 Trade Secret 1-5%
Trade Secret 06 Trade Secret 1-5%
Trade Secret 07 Trade Secret 1-5%
Trade Secret 08 Trade Secret 1-5%
Trade Secret 09 Trade Secret 1-5%
Trade Secret 10 Trade Secret 0.1-1%
Trade Secret 11 Trade Secret 0.1-1%
Trade Secret 12 Trade Secret 0.1-1%
Trade Secret 13 Trade Secret 0.1-1%
Trade Secret 14 Trade Secret 0.1-1%
Trade Secret 15 Trade Secret 0.1-1%
Trade Secret 16 Trade Secret Total concentration of all substances 100%