Group I Base Oils are made using solvent extraction or a solvent refining process. They are the least refined base oil and typically consist of a mix of different hydrocarbon molecules that cannot be distinguished in the refining process. They are used in certain Engine Oil applications along with industrial applications and marine lubricants.

Group II Base Oils that are manufactured through a process called hydrocracking, which breaks downs larger hydrocarbon molecules into smaller one. Group II Oils tend to have a higher purity level than Group I . GII oils can be used in the majority of lubricant applications and are arguably the most commonly used out of all the groups.

Group III and III+ Base Oils are produced by severe hydrocracking, which applis additional heat and pressure to the refining process. This produces a purer base oil with higher quality.