Are there any viscosity index improvers in Group III oil? I posed this question in a PM to Dr. Haas a couple of days ago, but he hasn't got back to me yet.
Does Group III synthetic oil have VI's?
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When Dr. Haas wrote that, he didn't mention which group of synthetics have no VI's; hence my question.
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When Dr. Haas wrote that, he didn't mention which group of synthetics have no VI's; hence my question.
With all due respect to the good doctor, that is a gross over-generalization. The fact is that very few synthetics on the market, whether they are made from Group III or Group IV, have no VI improvers in the mix.
I respect the Dr. as a person and am sure he is very intelligent but he has written too many incorrect things on the subject of motor oil and lubrication to make his writings a great source of education. I know that sounds harsh and don't mean it that way but how else can I get the point across?
Uh oh. . .
There are many Gp IV oils with vis improvers.
Its one of the reason I love my synthetic 10w30 - less likely to have VII's, and the good ones won't have any.
Are you sure about that?
It must be true, I read it on the internet.
Well PAO and ester based synthetic 10w30s shouldn't need VIIs, but I could be wrong; I'm basing it off of info from BITOG (but it was from knowledgable members).
We need bruce or molakule to chime in.
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When Dr. Haas wrote that, he didn't mention which group of synthetics have no VI's; hence my question.
With all due respect to the good doctor, that is a gross over-generalization. The fact is that very few synthetics on the market, whether they are made from Group III or Group IV, have no VI improvers in the mix.
Agreed. Dr Hass' statement is just wrong on way too many levels.
Rather than worry about the specific way that an oil is formulated, worry about how an oil works in your application. If you do oil analysis, and use someone like Terry to interpret, you will do yourself a favor, and avoid needless experimentation.
First: Oil, Ester or PAO WILL breakdown and degrade both chemical and physical they "will wear out"
Second: Some grades can be made with NO tradional VIII.
5/20 or 10/30 I think for sure thicker gardes unless straight grade no.
Second: Some grades can be made with NO tradional VIII.
5/20 or 10/30 I think for sure thicker gardes unless straight grade no.
Amsoil ACD 30WT(10W-30) has no VII, PAO based oil.
Your right about Amsoil, but we are getting off base here. The question was about group III oils. What's wrong with VI anyway?
That Amsoil ACD 30WT(10W-30) has a VI of 141.
Group III base oils typically have a VI in the 123 - 128 range (although Chevrons UCBO 7R (7cSt) is 135). Even with some esters I would think that if the VI of a GIII motor oil is over the low 130’s it would have VII’s.
Group III+ typically have a VI 140+. The wax isomerates in this article patentstorm… were 141 - 147.
So a blend of GIII’s (+ maybe some esters) could have a VI somewhere in the mid 140 range, and possibly as high as 150 without VII’s. Likely a little better than even a PAO blend.
Group III base oils typically have a VI in the 123 - 128 range (although Chevrons UCBO 7R (7cSt) is 135). Even with some esters I would think that if the VI of a GIII motor oil is over the low 130’s it would have VII’s.
Group III+ typically have a VI 140+. The wax isomerates in this article patentstorm… were 141 - 147.
So a blend of GIII’s (+ maybe some esters) could have a VI somewhere in the mid 140 range, and possibly as high as 150 without VII’s. Likely a little better than even a PAO blend.
I think you are going to have a difficult time trying to correlate the VI of the base oils with the VI index of the finished formulation.
The VI index of the finished motor oil reflects all the fluids in the blend, not just a single base oil.
GC 0w30 is probably a classic example with the 179 VI index. It's not likely that any of the synthetic base oils have a VI higher than 150 and Grp IV/V formulations do not need VI index improvers.
Actually, that is what I was alluding to.
For example, Amsoil XL 5w30 173 VI.
For a Group III (hydroprocessed) like the XL the base oils at best will probably be around 130 VI.
Mix …
Group III = 127
Group V = 135 - 150+ (?) …(maybe a small amount to increase solubility).
Final base oil mix = ~ 130
Since the finished 5w30 product has a VI of 173, it would require VII’s, … (ie. anything much over 130 for a GIII).
For PAO’s, they have about a 10 pt VI advantage over GIII’s -- so any PAO motor oil with a VI over 140 will likely have VII’s. The VI of Amsoil ASL 5w30 (PAO) is 185. It’s unlikely that the blend of base oils (Group IV + V) has a VI over 140 (or marginally over that) so to reach a VI of 185 requires VII’s.
5w30 synthetics usually have a VI of 160+ and 0w-30’s even higher, so these are guaranteed to have VII’s unless one used a large amount of high VI esters.
I think the vast majority of synthetic motor oils use VII’s. There are probably only a few that don’t, like some synthetic 10w30’s that come in around 135 - 140 VI.
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Boy, and to think there are people who merely change their oil "whenever" and basically use whatever oil is the cheapest and still get 200,000k miles without the slightest concern about varnish or any other aspect of the oil in their crankcase.....
What I meant was I can probably list a brand & viscosity that is an exception to any rule you can come up with that connects the VI of the base oil to the VI of the blend of fluids in the finished formulation.
In the earlier years of Bitog, Molekule explained the blending procedure for a PAO formulation several times. Classic PAO blends, non GF-4 formulations, do not need VI index improvers to meet the SAE J300 chart viscosity grade definitions.
While Terry Dyson's Z-Oil analysis several years ago, of GC 0w30 did not mention VI improvers, I would be very surprised to find out that GC with a VI of 179, had VI improvers in the formulation.
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