" Some Group III base oils outperform POA based Group IV"

Correct. I admit that I started the post early this morning that actually had to work and got distracted. But I think I was meandering into something a bit more wholistic regarding GTL overall, perhaps mainly SOPUS.
Absolutely fine, as I said, I was just pointing out that the quote in the OP was focusing on finished lubes, not bases specifically. I welcome a discussion about the bases themselves however!
It seems their North American oils all use at least a majority of GTL yet they have several lines of the typical "Good, Better, Best, & Extremely Bestist!"

What I'd really like to know is what is the difference between Shell RTG and the base Pennzoil synthetic vs. Platinum and and Ultra Plat. And Quaker State Synthetic. All have pretty low pour points and seem to perform well in certifications and look similar in PDS. But is there a tangible difference in some GTL "Group III+" oils as far as how they are hydrocracked? Or do they just add more Ester to the higher level oils like Ultra?

That's really kind of where I wanted to go, because it seems like there are very real differences even within GTL where some are on par with say VISOM and others might be pretty close to top PAO in performance...
Just speculation on my part, but it may be just how they blend the GTL bases. Back when they were first introduced (they may have more now), this was the slate:
Screen Shot 2020-09-26 at 10.12.39 AM.webp


The Noack on that 8cSt is quite impressive! This was back when we had Ultra 5w-30 introduced with its jaw-dropping low Noack of 6.6%. They then seemed to back away from the insanely low Noack oils (and changed-up the product offerings) and then stopped sharing Noack with us on PD sheets.

Of course we can't ignore that they likely have access to AN's through XOM, and I know that @Rod Knock was speculating that perhaps SOPUS is using XOM AN's in some of their higher tier finished lubes. If they were doing that instead of lower group bases to improve solubility, it might explain the artifacts you are seeing. Per that quote that @930.engineering made above, GTL is dry like PAO (though not as bad) so it needs help with solubility too. This is typically done using lower group "carrier" oils but it can also be achieved with POE and AN's. There wouldn't be need for POE with Group III, but AN's could definitely work to "polish" the combo, if we are making some somewhat educated guesses with regards to what is going on.
 
Hasn't there been speculation that XOM was buying surplus GTL from SOPUS ?
I don't think it's speculation, I think we are quite confident that they are. They are using GTL, and I did previously speculate they were potentially producing it in-house (they do have some NG reforming capacity) but the assumption was that they were just buying it from Shell, since they cancelled what would have been their equivalent to Pearl.
 
Pennzoil website states that "Synthetics made from Group III oil can, in some cases, outperform those made in Group IV oils in some areas". Do you guys agree with this? If so which Group III oil is known to outperform Group IV oils?
If they are referring to GTL, they are telling the truth and It's not a marketing.
GTL has better Noack volatility and very comparable oxidation stability, but it's not on bar with PAO in low temperature performance due to inherently lower viscosity index, however it can be improved with some additives to make 0w oils, but I wouldn't use it anyway in that case. A 0w PAO-based is better in this application.
 
If they are referring to GTL, they are telling the truth and It's not a marketing.
GTL has better Noack volatility and very comparable oxidation stability, but it's not on bar with PAO in low temperature performance due to inherently lower viscosity index, however it can be improved with some additives to make 0w oils, but I wouldn't use it anyway in that case. A 0w PAO-based is better in this application.
That's always been my understanding as to the only benefit of pao, the low temp characteristics.
 
It’s not the only one. Despite the claim to the contrary there are still other properties that are superior, oxidation resistance being one of them. The structure of the molecule lends to that.
Excellent! I forgot about that (y)
 
It’s not the only one. Despite the claim to the contrary there are still other properties that are superior, oxidation resistance being one of them. The structure of the molecule lends to that.
I would agree with you when comparing base stock to base stock. What I was stating is with the additive response difference in a true A, B comparison a finished product the group III formula was measurably improved over the PAO. I am not knocking PAO in any way, we use quite a bit of it.
 
I would agree with you when comparing base stock to base stock. What I was stating is with the additive response difference in a true A, B comparison a finished product the group III formula was measurably improved over the PAO. I am not knocking PAO in any way, we use quite a bit of it.
Yes always a challenge to thread the needle when discussing base stock properties absent a finished product. And you’d know more about that than me. Thanks for the detail.
 
Correct. I admit that I started the post early this morning that actually had to work and got distracted. But I think I was meandering into something a bit more wholistic regarding GTL overall, perhaps mainly SOPUS.

It seems their North American oils all use at least a majority of GTL yet they have several lines of the typical "Good, Better, Best, & Extremely Bestist!"

What I'd really like to know is what is the difference between Shell RTG and the base Pennzoil synthetic vs. Platinum and and Ultra Plat. And Quaker State Synthetic. All have pretty low pour points and seem to perform well in certifications and look similar in PDS. But is there a tangible difference in some GTL "Group III+" oils as far as how they are hydrocracked and the quality of their basestocks? Or do they just add more Ester to the flagship oils like Ultra?

That's really kind of where I wanted to go, because it seems like there are very real differences even within GTL where some are on par with say VISOM and others might be pretty close to top PAO in performance...
I do have a question on Platinum and Ultra Platinum. I do not see D1 G2/G3 label on Ultra. Ultra uses magnesium where regular platinum does not. Would that be a issue in the qualifications for Dexos?
 
I do have a question on Platinum and Ultra Platinum. I do not see D1 G2/G3 label on Ultra. Ultra uses magnesium where regular platinum does not. Would that be a issue in the qualifications for Dexos?

They both have magnesium.

https://pqia.org/pennzoil-platinum-full-synthetic-sae-5w-30-api-sp-motor-oil/
https://pqia.org/pennzoil-ultra-platinum-sae-5w-30-full-synthetic-motor-oil/

I would think it's more of a corporate decision by SOPUS not to get the Dexos approval for the lower sales volume of Ultra Platinum.
 
If they are referring to GTL, they are telling the truth and It's not a marketing.
GTL has better Noack volatility
They are comparable (trade punches so to speak) on Noack, at least in offerings that are of the same viscosity.

You saw the table I posted above.

- 4cSt GTL has a 12% Noack, SpectraSyn Plus PAO 4cSt has - 5cSt GTL has a 9% Noack, SpectraSyn PAO 5cSt has a 6.8% Noack
- 8cSt GTL has a 2% Noack, SpectraSyn PAO 8cSt has a 4.1% Noack

Of course Mobil's slate of PAO offerings is massively broader than what Shell had originally for GTL. Not sure if they've expanded it.
and very comparable oxidation stability, but it's not on bar with PAO in low temperature performance due to inherently lower viscosity index, however it can be improved with some additives to make 0w oils, but I wouldn't use it anyway in that case. A 0w PAO-based is better in this application.
PAO still comes out ahead on oxidation resistance (though GTL is better than other Group III bases) and yes, low temperature performance is where PAO dominates because it doesn't have the wax to crystallize that hydrocracked bases do. While PPD's will reduce the temperature at which that occurs, ultimately it can't rival PAO, and, PPD's degrade in service, which is why an oil is allowed to slip a Winter rating in service.
 
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So basically the only thing I know about the properties of oil is what I read on this forum, and I have not enough time to totally digest all the information here.
Can I infer from all this that if I NEVER start my BMW at a temp below 45° F , and have relatively short OCI, that I don't need 0WXX, or in other words no need to look for high PAO oils? Or even any PAO?

Is the addition of PAO the reason M1 got a reputation way back of causing oil leaks?
 
I would agree with you when comparing base stock to base stock. What I was stating is with the additive response difference in a true A, B comparison a finished product the group III formula was measurably improved over the PAO. I am not knocking PAO in any way, we use quite a bit of it.
This begs the question: who started the "truly synthetic" or "real synthetic" or "100% synthetic" marketing campaigns way back when?

- 4cSt GTL has a 12% Noack, SpectraSyn Plus PAO 4cSt has - 5cSt GTL has a 9% Noack, SpectraSyn PAO 5cSt has a 6.8% Noack
- 8cSt GTL has a 2% Noack, SpectraSyn PAO 8cSt has a 4.1% Noack

SpectraSyn 4:
1654702499704.png


SpectraSyn 6:

1654702597623.png


SpectraSyn 8:

1654702644670.png


Shell conveniently left out the viscosity at 40C. Those SpectraSyn values are excellent. 🤤

I'm wondering if a 0W-20 can be blended using SpectraSyn 8, ANs, and the additive package - which is what I suspect Mobil 1 EP 0W-20 is, I suspect.

Then again, looking at the pour point of each SpectraSyn fluid, couple with UOAs of EP 0W-20 that I've seen where it sheared down to 6.8~7 cSt @ 100C without fuel dilution (Pentastar Engine), and the fact that ANs and the additive package will decrease the pour point even further while increasing viscosity, somehow I doubt that Mobil uses just SpecraSyn 8 to blend EP 0W-20.

Maybe @High Performance Lubricants can tell us a little bit about how a 0W-20 is blended and maybe some other motor oil viscosities. I don't expect any proprietary information related to their products, just in broad terms.

I do have a question on Platinum and Ultra Platinum. I do not see D1 G2/G3 label on Ultra. Ultra uses magnesium where regular platinum does not. Would that be a issue in the qualifications for Dexos?
They both use the same additive package. The Ultra lineup is either where Pennzoil sells the GTL overproduction, or it's identical to the Platinum oils. Unless we perform an FTIR analysis (at the very least) on both products, we won't know for sure.

Interestingly enough, Pennzoil Platinum is Shell Helix Ultra SP, while Ultra Platinum has no direct correspondent in the Shell lineup. In other words, they concentrate their efforts on the "cheaper oil," though they are priced the same. It's just marketing at this point.
 
So basically the only thing I know about the properties of oil is what I read on this forum, and I have not enough time to totally digest all the information here.
Can I infer from all this that if I NEVER start my BMW at a temp below 45° F , and have relatively short OCI, that I don't need 0WXX, or in other words no need to look for high PAO oils? Or even any PAO?

Is the addition of PAO the reason M1 got a reputation way back of causing oil leaks?
If we are talking the 70's, yes, Mobil 1 would have been hard on seals. That was eventually corrected with the addition of POE to the base oil blend to improve seal compatibility.

HOWEVER

POE cleans. So do AN's.

So, if you have an engine that has significant deposits, and those deposits are blocking what would otherwise be leaks, and you put Mobil 1 in and it removes those deposits, you can of course end up with significant leakage. That's not a "fault" of the oil, it's just revealing an underlying problem you already had.
 
If we are talking the 70's, yes, Mobil 1 would have been hard on seals. That was eventually corrected with the addition of POE to the base oil blend to improve seal compatibility.

HOWEVER

POE cleans. So do AN's.

So, if you have an engine that has significant deposits, and those deposits are blocking what would otherwise be leaks, and you put Mobil 1 in and it removes those deposits, you can of course end up with significant leakage. That's not a "fault" of the oil, it's just revealing an underlying problem you already had.
I thought it always contained poe? I recently read the popular science article on synthetic oils from april 1976 and the mobil engineers did state they used poe to balance out pao being hard on seals. Not that it matters as that was so long ago. Just curious
 
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