ILSAC GF-3 and Group II base oil

Not open for further replies.
Oct 16, 2002
I had a question if the OTC dino oil I was using had a Group I or Group II base stock and I was told it was a blend of the two base stocks. Then I got this comment:

"In order to meet ILSAC GF-3 specification, the low viscosity grades, 5W-20, 5W-30 and 10W-30, of our motor oils include Group II base stock in their formulation."

From the reply is seems that the 10w-40, which is not GF-3, would therefore be only a Group I.

What is it about the GF-3 specs that would make it necessary for them to use some Group II for blending in the 5w-20,5w-30,10w-30 but not in the 10w-40 grade?

Can anyone figure this out?
Rant Mode: ON

Think of "GF-3" as "SL" + "Energy Conserving". You won't find any dino xW-40 oils meeting the "Energy Conserving" specification, ergo you won't find any of those oils listed as "GF-3", either. However, they do meet the API "SL" spec handily. Frankly there are too many overlapping specs and it's confusing perfectly intelligent people:

API "starburst" insignia for gasoline engines
"Energy Conserving"

If the oil companies would spend their money educating consumers that the API "donut" supplies ALL the salient information for North American motor oil specifications (API service grade, viscosity weight range, and whether the oil is graded "Energy Conserving" or not), they wouldn't have to come up with cutesy starburst seals, additional confusing alpha-numerics, and unintuitive abbreviations. How many people outside this forum know what "ILSAC" stands for? (Hint: if ILSAC's so "international", why do the European Union and Japanese OEMs have their own motor oil performance test sequences?)

Rant Mode: OFF (for the time being...)
Not open for further replies.