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That emblem on the bottle, ya know, the one that says Dexos1 Gen2, tells you its not just Full Synthetic but that it's additive package falls between the maximum AND minimum set by GM and those two numbers are pretty close together. For all intent and purpose they are the same. The MINIMUM requirement for the GM license is a pretty high mark. Higher than SAE or ILSAC.


The only thing that isn't on the bottle that should be is the cleanliness numbers. Tis the only real difference anymore among licensed Full Synthetics. It's a big difference but one whose field is leveled by a really good filter. 


Without even seeing a barnyard test I bought several cases of Kirkland for the wife's Terrain. 

Edited by Grumpy Bear
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  • 1 year later...
Posted (edited)

TBN / Antioxidant levels


Any regulars visit BITOG? I watch the VOA test maybe once a month. A also watch a few videos a month from guys like Project Farm and have noticed a scary trend. Two actually. The first being that there is a pretty large difference in TBN results depending on which lab does the testing. As much as there is between the two ASTM methods. 


It is expected that the ASTM D-2896 test done by manufacturing to be about 2 numbers higher than the results of ASTM D-4739. But there should not be that much difference between labs. That difference between VOA methods is also growing. That is the D-4739 result is now hovering 3 points lower that the vendors published Data Sheet values. 


The second one concerns me more. The gradual decline in virgin TBN in general. Oils are moving to the bottom of the 'normal' range. I've noticed this in the more popular oils that are tested a few times a year...this slow drift downward. 


Antioxidant levels likewise. They use to crowd the upper limit for the class and now seem to just make the minimum requirement. The newest diesel oil whose requirements have been lowered in the last SAE classification are almost the same as gas oils. They say in consideration of the particulate filter operation. Much like the lower levels when CATS were put on cars. 


Boiling the frog slowly 50 ppm at a time. 


From WIKI:  Potentiometric titration for used oils (Test method TBN ASTM D4739): a sample is dissolved in a solvent mixture of Toluene/ Propan-2-ol /Chloroform with 0.5% deionised water and then titrated with standardised alcoholic hydrochloric acid. The detection system is equivalent to the fresh oil method. The used oil method uses a less polar solvent and weaker titrant, which will not dissolve the wear metals produced during operation, hence it is more suitable to analyse used oils.[4]


The above bold really caught my eye. Especially the underlined portion. Let that turn over in the 'common sense' part of your gray matter. 


Under what 'normal' operating conditions would acid levels in running motor be strong enough to dissolve wear metals? NEVER! SO.....those extra two or three points of so called acid reserve are not really available are they? Meaning??? When the UOA TBN number is low 4....she's done. 


If you haven't notice the upper end of the oil food chain just a few years ago had a VOA TBN of 12 or more and now those same outfits are testing 8  and mid pack oils that were 8 or 9 and now 6. 


Couple that with lower antioxidant levels and????


Once again SHORTER OCI'S


In the most recent Project Farm he test COSTCO Kirkland and obtains both VOA and UOA.





Virgin acid number was like 1.6 and he runs TBN down to 1?

TAN will be 3 ish by the time the TBN is 3 ish.  

Edited by Grumpy Bear
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There is a big push to increase OCI lengths to at least 7,500 miles. I won't get into the reasons. There is an equally hard push to lower both detergent, specifically calcium, and phosphorus levels. To recap we are pushing to increase OCI while at the same time removing the chemicals that permit extended OCI's? Sad but true. And it looks like we are going to lie, deceive and manipulate to get what we want.....again..... We don't have allot of tools to works with here as those that want what they want also happen to be in charge of the 'facts'. Don't confuse that with having the truth. 


What does that leave us? Common sense and history! 




When you read this link study the chart. Study how this charts data was obtained. 




After you review this second link take particular note of this quote from that article: 


But what about the longer-term impact?

The issue is that these other weak base components can be used up in practice. For example, anti-oxidant reacts with oxygen and is consumed; as a result, the TBN decreases. To prevent this TBN drop, some lube oil companies remove these components from the lubricant formulation. The perception is extended drain performance, which is confirmed by laboratory routine analysis testing, but the long-term effect is dirty engines, more oil deposits, increased downtime and higher maintenance costs. (end quote)


Last piece of the puzzle: 






There it is. The link between TBN/TAN and Wear and the beginning of enough information to use common some sense.


Did you take note that Machinery Lubrication made a POINT of WHICH TBN test to use? That Q8 Oil acknowledges the truth that deposit formation WILL result as antioxidants deplete and that this is reflected in a rise in TAN. Finally that wear accelerates rapidly AFTER the TAN and TBN cross. But pay closer attention to the graphs. Much closer attention. This is the data. 


Wear begins to rise IMMEDIATELY upon the beginning of the decline in TBN and rise of TAN. IMMEDIATELY!!. 


Well we can't be changing our oil after every trip to the grocery store now can we. But we can take notice that shortly after the TBN and TAN cross the rate of wear gets out of control and it's exact point after the crossing line is fairly  unpredictable. 


But we are looking at a bit more that straight up wear. We are also looking at cleanliness and as Q8 pointed out: The perception is extended drain performance, which is confirmed by laboratory routine analysis testing, but the long-term effect is dirty engines, more oil deposits, increased downtime and higher maintenance costs.


The result of some TBN games being played with metal deactivators and Q8 makes note at the end of the article this cute little bit of information: It is time to say goodbye to the 50% TBN urban legend. Performance of the engine oil should be the leading consideration and the SGEO should be replenished at the right limit value; this will likely mean specific limits for some oils instead of generic limits for all oils.


So..."Trust me as I lie to you"? That sentence says we will play with the chemistry but not with them all and we will tell you when when the use that little word SOME


That SOME word is a word used to intentionally confuse. Happy for us they leave us bread crumbs. The graph...the data. 


The Machinery Lubrication article and Q8 articles, if you did not catch it, use different test for TBN and it is the use of the stronger acid test used in the Q8 article that is the basis for creating the confusion. The results of the stronger acid test will be affected by the additional chemicals used to boost TBN artificially. Not because they interfere but because the strong acid CONSUMES the metals the deactivators work on. THUS the reason Machinery Lubrication (Polaris Labs) tells us to use the weaker acid test so that we are testing ONLY the OVERBASED DETERGENT LEVELS. 


Machinery Lubrication also make this significant note: Historical test data shows the relationship between TBN and TAN to be quite consistent.......The two will meet at around 3.15 to 3.5. 


Again consult the graph in the Machinery Lubrication article. It is consistent and it is indefinite. AROUND is a big word and the graph displays that nicely. 


You draw your own conclusions but in my world this means I change oil on a TBN of 4 as the floor and how long the oil last in hours, miles or TBN units will depend on the VOA TBN done by the weaker method. 



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  • 2 weeks later...

Quick question! 


If your motor starts using oil because the rings have collapsed varnished, coked, stuck...










Edited by Grumpy Bear
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A long but good read and if your patient enough you will find out how much of what you've heard about esters is pure garbage. 




Here's an example from the article: 


"Some say esters compete so vigorously for the metal surfaces that they crowd out necessary additives. However, many additives are active enough to displace an ester from a surface. Expertise and experience are important here, as some additives do not work well with synthetic esters".


Some say turns into THEY WILL in a forum setting. 


Your trust your blender or you don't.



I trust mine. 

Edited by Grumpy Bear
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  • 1 month later...

Unusable at what TBN?





Unrelated to TBN but I just saw a Blackstone UOA Report where the 100 C viscosity was well under the lower limit and Blackstone telling this guy not to worry...push it further...Oh...and not reported TBN. 


Yea, look at the last line of their comments!



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