Latest info on ExxonMobil synthetic base stocks

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I haven't gone through all of this -- there is lots and lots of info to absorb here!

Two things struck me though:

(1) It turns out that the base stocks, not just the viscosity-index improver (VII), also shear. This is especially true with the advanced synthetic base stocks such as SpectraSyn Ultra™ PAO ExxonMobil makes, which have complicated molecules. They shear as much as 50%!

(2) Including an ester base stock in finished oil quadruples the Sequence IVA wear (API valvetrain wear test for gasoline engines)! This is especially scary as most Mobil 1 oils must include an ester base stock since PAO on its own is not stable. Lately they have possibly started using alkylated naphthalene instead of esters in some of their oils. The reason why esters increase wear so much is because they compete for the metal surfaces and they prevent the antiwear/extreme-pressure/friction-modifier additives from adhering to the metal surfaces.

ExxonMobil Chemical advanced synthetic base stocks

Exxon Mobil synthetic lubricant base stocks formulations guide (2017)
 
So you have a very high level concerns concerning ExxonMobil oil??

I'm sure that you know TGMO is made by ExxonMobil as well.

It is not my intention to seem like I am giving you a hard time here. I do not mean this in that way.
 
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Originally Posted By: bbhero
So you have a very high level concerns concerning ExxonMobil oil??

I'm sure that you know TGMO is made by ExxonMobil as well.

It is not my intention to seem like I am giving you a hard time here. I do not mean this in that way.

Yes, but TGMO is Group III -- no PAO and possibly wear-inducing ester.

I did use M1 0W-40 SN recently and a lot of Mobil Delvac Super 1300 15W-40 CJ-4/SM in the past though.

I've corrected the link for the first document above.
 
WOW! I just got done responding to Jaha24k's post about TGMO oil.. and here I found this next post talking about WHY Mobil is shearing down!

I have seen this myself. Look up my UOA on my scion tc! That is stored, and it is thinning/shearing on it's own! The engine isn't even being used, just sitting!

EDIT: the low wear numbers on the tC is because it wasn't being used, just stored. On the civic, the columns (on my UOA's) that show titanium are the TGMO usage intervals. Yes the wear is nothing bad, but I still didn't like how quickly it sheared.

EDIT2: I had been using TGMO Conventional..

Hey if the Mobil fans want to debate it go ahead but I've already had first hand experience with what the offerings from Mobil are up to. I don't care for it. Yes I know that TGMO (toyota) has Mobil make their brand of oil, and to their own recipe, but the base stocks are definitely not as good as they used to be.

This post.. THANKS Gokhan! It makes complete sense of what I experienced!
 
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Originally Posted By: Gokhan
(2) Including an ester base stock in finished oil quadruples the Sequence IVA wear (API valvetrain wear test for gasoline engines)! This is especially scary as most Mobil 1 oils must include an ester base stock since PAO on its own is not stable. Lately they have possibly started using alkylated naphthalene instead of esters in some of their oils. The reason why esters increase wear so much is because they compete for the metal surfaces and they prevent the antiwear/extreme-pressure/friction-modifier additives from adhering to the metal surfaces.

I see that in their formulation guide (second document), they are indicating only 2% ester in their PAO formulations. In their first document where they report a quadrupling of the Sequence IVA wear, they used 10% ester. My guess is that in most oils Mobil 1 sells, the ester concentration is around 2% and doesn't cause a significant increase in Sequence IVA wear as a result.

Clearly some time ago, during the API SM days, Mobil 1 was having a problem with Sequence IVA when Castrol reported their test results. This was also verified by many consumer UOA's such as on BITOG that showed very high iron numbers (excessive valvetrain wear). That could have been due to excessive use of esters in their formulations back then. This problem has been addressed and corrected by Mobil 1 since then.

I wish the Sequence IVA wars would start again and we would know which oil actually causes less wear.
smile.gif


http://www.jobbersworld.com/QSletter.htm

http://www.jobbersworld.com/March%2020,%202009.htm
 
Originally Posted By: Gokhan
...Clearly some time ago, during the API SM days, Mobil 1 was having a problem with Sequence IVA when Castrol reported their test results. This was also verified by many consumer UOA's such as on BITOG that showed very high iron numbers (excessive valvetrain wear). That could have been due to excessive use of esters in their formulations back then. This problem has been addressed and corrected by Mobil 1 since then...

Makes me all the more confident with my choice of PP with the GTL basestock.
 
Originally Posted By: turnbowm
Originally Posted By: Gokhan
...Clearly some time ago, during the API SM days, Mobil 1 was having a problem with Sequence IVA when Castrol reported their test results. This was also verified by many consumer UOA's such as on BITOG that showed very high iron numbers (excessive valvetrain wear). That could have been due to excessive use of esters in their formulations back then. This problem has been addressed and corrected by Mobil 1 since then...

Makes me all the more confident with my choice of PP with the GTL basestock.


If PAO shears, I'm sure GTL does too.
 
Originally Posted By: Gokhan
Originally Posted By: Gokhan
(2) Including an ester base stock in finished oil quadruples the Sequence IVA wear (API valvetrain wear test for gasoline engines)! This is especially scary as most Mobil 1 oils must include an ester base stock since PAO on its own is not stable. Lately they have possibly started using alkylated naphthalene instead of esters in some of their oils. The reason why esters increase wear so much is because they compete for the metal surfaces and they prevent the antiwear/extreme-pressure/friction-modifier additives from adhering to the metal surfaces.

I see that in their formulation guide (second document), they are indicating only 2% ester in their PAO formulations. In their first document where they report a quadrupling of the Sequence IVA wear, they used 10% ester. My guess is that in most oils Mobil 1 sells, the ester concentration is around 2% and doesn't cause a significant increase in Sequence IVA wear as a result.

Clearly some time ago, during the API SM days, Mobil 1 was having a problem with Sequence IVA when Castrol reported their test results. This was also verified by many consumer UOA's such as on BITOG that showed very high iron numbers (excessive valvetrain wear). That could have been due to excessive use of esters in their formulations back then. This problem has been addressed and corrected by Mobil 1 since then.

I wish the Sequence IVA wars would start again and we would know which oil actually causes less wear.
smile.gif


http://www.jobbersworld.com/QSletter.htm

http://www.jobbersworld.com/March%2020,%202009.htm



Mobil could have had an issue with their SM formula, but, I don't think that still holds true today. They say the Mobil 1 high mileage provides unsurpassed wear protection in the API sequence IVA.

https://mobiloil.com/en/motor-oils/mobil-1/mobil-1-high-mileage
 
Originally Posted By: turnbowm
Originally Posted By: Gokhan
...Clearly some time ago, during the API SM days, Mobil 1 was having a problem with Sequence IVA when Castrol reported their test results. This was also verified by many consumer UOA's such as on BITOG that showed very high iron numbers (excessive valvetrain wear). That could have been due to excessive use of esters in their formulations back then. This problem has been addressed and corrected by Mobil 1 since then...

Makes me all the more confident with my choice of PP with the GTL basestock.
It doesn't take much does it.
 
Originally Posted By: OVERKILL
Originally Posted By: turnbowm
Originally Posted By: Gokhan
...Clearly some time ago, during the API SM days, Mobil 1 was having a problem with Sequence IVA when Castrol reported their test results. This was also verified by many consumer UOA's such as on BITOG that showed very high iron numbers (excessive valvetrain wear). That could have been due to excessive use of esters in their formulations back then. This problem has been addressed and corrected by Mobil 1 since then...

Makes me all the more confident with my choice of PP with the GTL basestock.

If PAO shears, I'm sure GTL does too.

My understanding is that these (SpectraSyn Ultra™ PAO) are special very high-viscosity base stocks used in machining applications (neat oil). I doubt the PAO base stocks used in motor oil shear more than a small fraction of a percent, which would be negligible.

Yes, I think esters are a concern but I'm sure Mobil 1 is keeping their concentration at a minimum to avoid any issues with surface competition with the additives.
 
That document is XOM marketing material, so it is designed to persuade the audience into making certain purchase decisions. I’m not saying that it is full of bad or incorrect data. I’m saying that the data shown are cherry-picked to convey the message they want the audience to believe. If they want to show how amazing alkylated napthalene is, they find a particular ester used at a particular concentration along with a particular rest of the formulation in a particular test in which it caused the oil to allow a lot more wear than did the formulation with alkylated napthalene.

Mobil was using alkylated napthalene in Mobil 1 back when they sold the Tri-Synthetic formulation. It had PAO, AN, and ester. I do not know if that was the first M1 formulation that used AN.

The large and very large PAO molecules can be sheared in that severe test largely because they are that large. It comes with the territory of being that large. Other molecular attributes also effect shear stability, as well, but molecular size is a very strong factor in shear stability.

So, don’t extrapolate too far beyond the particular test data that are being shown in that document.
 
Originally Posted By: njohnson

Mobil could have had an issue with their SM formula, but, I don't think that still holds true today. They say the Mobil 1 high mileage provides unsurpassed wear protection in the API sequence IVA.


Now it's the Volvo T-13 oxidation test that Delvac 1300 Super 15w-40 is failing. That test is required to meet CK-4 and other manufacturers certifications.

Delvac failing volvo T-13

https://www.bobistheoilguy.com/forums/ubbthreads.php/topics/4788016/Shell_vs_Delvac#Post4788016

Ed
 
ALL VIs shear off eventually this is why air cooled engines use straight oils or oils with much fewer VI improvers like 20w-50.
This is also why ANY oil with a wide range should be avoided.
 
Originally Posted By: edhackett
Originally Posted By: njohnson

Mobil could have had an issue with their SM formula, but, I don't think that still holds true today. They say the Mobil 1 high mileage provides unsurpassed wear protection in the API sequence IVA.


Now it's the Volvo T-13 oxidation test that Delvac 1300 Super 15w-40 is failing. That test is required to meet CK-4 and other manufacturers certifications.

Delvac failing volvo T-13

https://www.bobistheoilguy.com/forums/ubbthreads.php/topics/4788016/Shell_vs_Delvac#Post4788016

Ed

Ha! So much with the Mobil Delvac 1300 Super 15W-40 -- an oil of which I used the CJ-4/SM version religiously in the past!

So, Delvac 15W-40 uses very cheap base stocks. Interesting.
 
Mobil Delvac 1300 Super 15W-40 failing the Volvo T-13 rest is likely the fault of the antioxidants, not the base oils. When degradation suddenly skyrockets, it’s generally when the antioxidants were depleted to a level that causes the base stock(s) to be attacked relentlessly. No base oils are immune from the effects but they do respond differently. The antioxidants act as free radical scavengers and peroxide decomposers. The antioxidants are like the army protecting the king. When the army can no longer provide protection, the king gets assaulted.
 
Originally Posted By: JAG
Mobil Delvac 1300 Super 15W-40 failing the Volvo T-13 rest is likely the fault of the antioxidants, not the base oils. When degradation suddenly skyrockets, it’s generally when the antioxidants were depleted to a level that causes the base stock(s) to be attacked relentlessly. No base oils are immune from the effects but they do respond differently. The antioxidants act as free radical scavengers and peroxide decomposers. The antioxidants are like the army protecting the king. When the army can no longer provide protection, the king gets assaulted.

Aren't those additive packs pretty standard though? My guess would be that the antioxidant got depleted not because it was an inferior antioxidant but the base oil was oxidizing too fast because of its low API Group # and eating it away.
 
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