Originally Posted By: mac9128
Thank you, I appreciate it. Any word on the group III, IV, V oil subject?
Group 3, 4, 5 refers to the basestock used.
"Group I base stocks are composed of fractionally distilled petroleum which is further refined with solvent extraction processes to improve certain properties such as oxidation resistance and to remove wax. Group II base stocks are composed of fractionally distilled petroleum that has been hydrocracked to further refine and purify it. Group III base stocks have similar characteristics to Group II base stocks, except that Group III base stocks have higher viscosity indexes. Group III base stocks are produced by further hydrocracking of Group II base stocks, or of hydroisomerized slack wax, (a byproduct of the dewaxing process). Group IV base stock are polyalphaolefins (PAOs). Group V is a catch-all group for any base stock not described by Groups I to IV. Examples of group V base stocks include polyol esters, polyalkylene glycols (PAG oils), and perfluoropolyalkylethers (PFPAEs). Groups I and II are commonly referred to as mineral oils, group III is typically referred to as synthetic (except in Germany and Japan, where they must not be called synthetic) and group IV is a synthetic oil. Group V base oils are so diverse that there is no catch-all description."
