I'm afraid group III is hydrocracked.

Silkolene uses Group IV and V in the PRO products and these are the best.

This is how the Groups work:

These are the API base oil classifications which are used for base oil interchange and blending guidelines. They are based on sulphur content and saturate level. Saturate level refers to the carbon - carbon & carbon - hydrogen bonding mechanism within the molecule; high saturates considered to give a more stable product and to be generally more beneficial.

Conventional solvent refined paraffinic stocks as used in vast majority of formulations are Group 1. Group 2 not normally available in the UK. Group 3 are the high VI hydrocracked stocks.

All PAOs fall into Group 4. Group 5 is anything else, usually esters.

Cheers
Simon