Explanation of Groups please

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30
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Baltimore area
I'm new to this group. Thought I knew something about oil, but after reading some of these posts, it seems I don't know much. Can someone please explain the different Groups (GroupII, or III ect....) to me. I think I figured out UOAs. Thanks for your help.
 
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8,937
Location
SC
quote:
Originally posted by wheels: I'm new to this group. Thought I knew something about oil, but after reading some of these posts, it seems I don't know much. Can someone please explain the different Groups (GroupII, or III ect....) to me. I think I figured out UOAs. Thanks for your help.
Keep in mind that the "groups" only refer to the BASE OIL that serves as the foundation of a finished motor oil. The more you read on this board, the more you'll come to know which finished motor oils are built on which groups. As for an explanation of what these groups are, this is a simplified version: Group I = refined crude, with the wax removed by solvent treating and SOME of the impurities removed through hydrogen finishing. Group II and II+ = refined crude, with the wax CONVERTED to "oil molecules" by isomerization, and the impurities removed or converted by "cracking" their molecular structure. Group III = same as above, but with more of the wax converted and more of the impurities cracked. SOME Group III base oils are pure wax isomerates, meaning they are made FROM the wax removed while making a Group I oil. Typically these type Group III oils have much less impurities than other Group IIIs, as well as much higher VIs (viscosity indexes). Group IV = synthetic hydrocarbons known as Polyalphaolefins or PAO. This is the primary element of the base oil blends used in Mobil 1 and Amsoil. Group V = all oils not included in the other groups. For motor oils, this is primarily esters, which in some synthetics make up 50% or more of the base oil blend (along with Group III or Group IV), but in most synthetics oils that contain esters, there is more Group IV.
 

wheels

Thread starter
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30
Location
Baltimore area
Thanks Al for the Welcome and the info. Now it's as clear as mud to me. Only kidding. I did understand some of it, and some I didn't. It looks like it boils down to GroupIIIs vs PAOs. Am I right? It would appear that GroupIII is better than I or II. And then there are PAOs, which appear to be better than groupIII. Am I on the right track? After seeing G-Man's post, I believe I've oversimplified it. [ May 26, 2003, 10:50 AM: Message edited by: wheels ]
 
Messages
8,937
Location
SC
quote:
Originally posted by wheels: Thanks Al for the Welcome and the info. Now it's as clear as mud to me. Only kidding. I did understand some of it, and some I didn't. It looks like it boils down to GroupIIIs vs PAOs. Am I right? It would appear that GroupIII is better than I or II. And then there are PAOs, which appear to be better than groupIII. Am I on the right track? After seeing G-Man's post, I believe I've oversimplified it.
If you're just comparing base oils, then yes, Group III is better than Group II and I, and Group IV is better than Group III. But keep in mind that it's how the finished motor oil performs that matters most. Schaeffers is a blend of Group IV and Group II (or Group III for the 5w30), and it performs just as well as most fully synthetic oils. It's in extreme conditions where a motor oil formulated with nothing but Group IV and Group V will shine. You will need such an oil for sub-zero arctic temps, and in very high temps, such an oil will perform better.
 

Patman

Staff member
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21,988
Location
Oakville, Ontario
quote:
Originally posted by wheels: Never heard of Schaeffers before. Where can I learn more about it? I've never seen it in the store either.
Do a search on here, we've discussed it quite a lot here. You won't find it in too many stores, but if you look up to your left hand corner, you'll see a link for one of our site sponsors, Mills Outdoor Power Equipment, who sells it. I'm using Schaeffer Oil in my 95 Firebird, and have been very impressed with it so far.
 
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