grp question
- Thread starter pp_rp
- Start date
- Status
I'll take a shot at it: Group IV is more synthetic than the others; it's comprised of poly-alpha-olephin.
- Joined
- Dec 30, 2006
- Messages
- 29,558
My understanding in the synth oils is:
III-hydrocracked conv based oil that`s extremely refined
IV-PAO based synth
V-Ester based synth
III-hydrocracked conv based oil that`s extremely refined
IV-PAO based synth
V-Ester based synth
And GrpI & II are processed to a much lesser extent than GrpIII. BTW, all this stuff gets blended and additive put in.
If you can avoid getting caught in the technical nature, read this:
www.chevron.com/products/prodserv/BaseOils/docs/npra_paper.pdf
Bottomline is GrpIII (highly processed) achieve nearly the results of true synthetic GrpIV and much better than GrpII. (better V.I. & cold cranking, better volitility at high temp., better oxidation stability). See pages 20-22.
What is not said is GrpIII is much less costly to produce than GrpIV. Hense lots of sale/rebate deals on GrpIII 'synth's'. I've been paying no more than $1-2/qt for well over a year. Since I don't do extended drains, this makes GrpIII attractive to me.
If you can avoid getting caught in the technical nature, read this:
www.chevron.com/products/prodserv/BaseOils/docs/npra_paper.pdf
Bottomline is GrpIII (highly processed) achieve nearly the results of true synthetic GrpIV and much better than GrpII. (better V.I. & cold cranking, better volitility at high temp., better oxidation stability). See pages 20-22.
What is not said is GrpIII is much less costly to produce than GrpIV. Hense lots of sale/rebate deals on GrpIII 'synth's'. I've been paying no more than $1-2/qt for well over a year. Since I don't do extended drains, this makes GrpIII attractive to me.
Last edited:
If JAG sees this thread, he'll explain everything to you.
Mobil 1 vs. Castrol in a late 1990's law suit - Castrol won the right to state their oil as Grp III even though it was not PAO based. The courts decided that there was enough processing done on the dino molecules (not just cleaning the dino but adding to the molecule) that it could be called a man-made synthetic. In the end Grp III is an extremely hydrogenated (and therefore extremely pure) dino molecule.
To get Grp III, oil goes thru extrememly high temp (like 700deg) processing where it's put in the presence of a catalyst that makes the hydro-carbon chains want to take on more hydrogen until it's saturated (all this is done in the presence of plenty of hydrogen, so there's plenty available to bond with). In the end the process typically strips away essentially all (or like 99% - I'm not sure of the %) impurities (impurities on the carbon chain include nitrogen, sulfur and carbon "rings" - these "rings" actually get straightened out into proper carbon chains in this process - and then they get hydrogenated into grp III, and the nitrogen and sulfur get removed and replace by hydrogen). When the process is complete, you have a carbon chain that has a hydrogen at every bonding pt. This oil is essentially clear - and I've heard you could cook with it. Grp IIIs get their darker color from the additives. So you've got the PUREST dino oil possible - no sulfur or nitrogen or carbon rings to cause harmful chem reactions in your engine. And the performance of the Grp IIIs are in the neighborhood of the GrpIV/V - but Grp IV/Vs still rule in most applications.
The Grp IVs are apparently made from gas molecules. I don't know much about them (nor about the grp Vs). Apparently a lot of the oils needed performance properties can actually be designed into the molecule - thus less of a need for certain additives. Someone else will have to explain Grp IV/Vs. And clarify if I missed anything on Grp IIIs (or giving any mis-info - I think my description is fairly accurate though).
To get Grp III, oil goes thru extrememly high temp (like 700deg) processing where it's put in the presence of a catalyst that makes the hydro-carbon chains want to take on more hydrogen until it's saturated (all this is done in the presence of plenty of hydrogen, so there's plenty available to bond with). In the end the process typically strips away essentially all (or like 99% - I'm not sure of the %) impurities (impurities on the carbon chain include nitrogen, sulfur and carbon "rings" - these "rings" actually get straightened out into proper carbon chains in this process - and then they get hydrogenated into grp III, and the nitrogen and sulfur get removed and replace by hydrogen). When the process is complete, you have a carbon chain that has a hydrogen at every bonding pt. This oil is essentially clear - and I've heard you could cook with it. Grp IIIs get their darker color from the additives. So you've got the PUREST dino oil possible - no sulfur or nitrogen or carbon rings to cause harmful chem reactions in your engine. And the performance of the Grp IIIs are in the neighborhood of the GrpIV/V - but Grp IV/Vs still rule in most applications.
The Grp IVs are apparently made from gas molecules. I don't know much about them (nor about the grp Vs). Apparently a lot of the oils needed performance properties can actually be designed into the molecule - thus less of a need for certain additives. Someone else will have to explain Grp IV/Vs. And clarify if I missed anything on Grp IIIs (or giving any mis-info - I think my description is fairly accurate though).
That's a pretty good description, just two corrections.
It was not a law suit but a complaint filed with the FTC and there was no court rueling, but an FTC decision in favor of Castrol.
It was not a law suit but a complaint filed with the FTC and there was no court rueling, but an FTC decision in favor of Castrol.
It depends on one's definition of "full synthetic".
The point is GrpIII performance is nearly that of GrpIV in almost all applications and I can get is at cost-effective price. I can't really use $6/qt oil as I use ~18qt in 6K OCI.
I have seen Shell Helix Utra 5W30 PAO spec'd for VW and Audi petro turbo. Turbo's might be a class where you may want/need Grp IV or V.
man, i haven't seen this question asked here since i first joined back in august last year.
well back then i joined in the midst of all this mobil-1 hating, claims they were using grp-3 base stocks and yata yata. people were saying group 3's are ____ and castrol is ____ and claims that mobil switched to group 3 without telling everyone, blah blah blah.
point is these days group 3 seems to be accepted here as very good. group 4 has a certain edge over group 3, but i guess its completely unnecessary unless your running a turbo or something like that. in fact, i was all caught up in the group 4 craze, using only group 4 oil. but to be honest, today, i think its all the same ____.
well back then i joined in the midst of all this mobil-1 hating, claims they were using grp-3 base stocks and yata yata. people were saying group 3's are ____ and castrol is ____ and claims that mobil switched to group 3 without telling everyone, blah blah blah.
point is these days group 3 seems to be accepted here as very good. group 4 has a certain edge over group 3, but i guess its completely unnecessary unless your running a turbo or something like that. in fact, i was all caught up in the group 4 craze, using only group 4 oil. but to be honest, today, i think its all the same ____.
like wendy's commercials: do what tastes right.
Grp IIIs are a thing of beauty IMO. What oil should've always been.
Here's my two cents:
While Group III oils are not Group IV (PAO) oils, you won't find naturally occuring Group III oils so in a sense it is truly synthetic. A reaction is forced to manufacture Group III products.
Group IV (PAO) oils were not created out of thin air in the lab, it also is the result of something natural being processed. I have read a little bit about this process but didn't really understand enough to pass anything of value along.
While Group III oils are not Group IV (PAO) oils, you won't find naturally occuring Group III oils so in a sense it is truly synthetic. A reaction is forced to manufacture Group III products.
Group IV (PAO) oils were not created out of thin air in the lab, it also is the result of something natural being processed. I have read a little bit about this process but didn't really understand enough to pass anything of value along.
- Status
Similar threads
