quote:Originally posted by sprintman:
Does that mean Group I?
As previous stated by MolaKule, paraffinics are present in Groups I - III. Group IIIs contain the highest percentage of iso-paraffins (very desirable) courtesy of severe hydro-processing having catalytically processed the lion's share of residual, undesirable, normal paraffinics, waxes, naphthenics, and aromatics to iso-paraffinics. (This gets to the heart of why Castrol prevailed in its squabble with Exxon/Mobil over the use of the term, "synthetic".) Of the three listed groupings, Group I has the highest percentage of undesirable molecules. When you see catch phrases such as Pennzy's "Pure Base" or ChevronTexaaco's "ISOSYN", I imagine the odds are pretty good that the marketing department's babble indicates use of Group II and/or Group II+ base stocks. (A "semi-synthetic"? No, let's not go there...)
[ October 25, 2003, 03:29 PM: Message edited by: Ray H ]