I found this on the Conoco site while looking for something else:
Quote:
Group III - Unconventional Base Oils
The API defines the difference between Group II and III base oils only in terms of V.I., viscosity index. Base oils with conventional V.I. (80-119) are Group II and base oils with an "unconventional" V.I. (120+) are Group III. Group III base oils are also called unconventional base oils (UCBO's) or very high V.I. (VHVI) base oils. Group II+ base oils have the same maximum V.I. as Group II (80-119), but have a higher minimum V.I. (110-119).
From a process standpoint, Group III oils are made by the same process as Group II oils, but the V.I. is increased by increasing the temperature of the hydrocracker. The product V.I. can also be increased by increasing the V.I. of the feedstock. Which is done by selecting the appropriate crude.
SURELY, there must be more/greater differences between II/II+ and III than VI. If not, and you have a compulsive/obsessive disorder, such as I have, and change your oil every 3000 miles, what is there to influence going to a gp III? Why wouldn't, for example only, say Pennzoil YB with a good VII add, which I assume it has, offer the same qualities as Pennzoil Platinum with a short OCI?
Same thought process for Valvoline Premium vs Synpower, or whoever else.
I assume I am missing something really important here.
Does increasing the temperature of the hydro-cracker also create a "purer" base oil? Does this mean the molecules of a gp III are more uniform that the molecules of a gp II+? ON the other hand, if gp III is just a higher VI gp II, why not go from gp II to gp IV if I were going to synthetic, given the small difference in price between III and IV?
Your knowledge greatly appdreciated.
Quote:
Group III - Unconventional Base Oils
The API defines the difference between Group II and III base oils only in terms of V.I., viscosity index. Base oils with conventional V.I. (80-119) are Group II and base oils with an "unconventional" V.I. (120+) are Group III. Group III base oils are also called unconventional base oils (UCBO's) or very high V.I. (VHVI) base oils. Group II+ base oils have the same maximum V.I. as Group II (80-119), but have a higher minimum V.I. (110-119).
From a process standpoint, Group III oils are made by the same process as Group II oils, but the V.I. is increased by increasing the temperature of the hydrocracker. The product V.I. can also be increased by increasing the V.I. of the feedstock. Which is done by selecting the appropriate crude.
SURELY, there must be more/greater differences between II/II+ and III than VI. If not, and you have a compulsive/obsessive disorder, such as I have, and change your oil every 3000 miles, what is there to influence going to a gp III? Why wouldn't, for example only, say Pennzoil YB with a good VII add, which I assume it has, offer the same qualities as Pennzoil Platinum with a short OCI?
I assume I am missing something really important here.
Your knowledge greatly appdreciated.