Low Starting TBN of New Synthetic Oils

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I noticed that Toyota's 0w-20 synthetic oil has a starting TBN of about 6, yet it is recommended for 10k oil changes. Some of the low SAPS oils for Euro cars also have very low starting TBNs. If I want my engine to stay clean for the duration of the 10k long drains, should I start adding BG MOA (or a similar additive) to supplement the oil's detergent package?
 

The Critic

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Starting TBN of 6 isn't much at all, especially with the acids that build-up from fuel dilution and short trip driving. I have about 1500 miles on the current fill and will run it for 5k.
 
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Starting tbn and tbn retention are 2 different things. I'd uoa at 5000miles to see how it goes in your engine. +1 if you get a TAN on the uoa
 

JHZR2

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Low saps in ga$$ers is incompatible wth US gasoline because of the sulfur content. If we had 15ppm ULSG like we have ULSD, it would be OK. I validated this running M1 ESP 5w-30 that met he current VW spec in our VW.
 

JHZR2

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Originally Posted By: Rand
Starting tbn and tbn retention are 2 different things. I'd uoa at 5000miles to see how it goes in your engine. +1 if you get a TAN on the uoa
Agree. But a retained TBN of 2 is worthless. It's like high school chemistry titrations. Get near the equivalence point and the buffer is far slower - the kinetics are concentration dependent, and the concentration is low. Don't want to SI jest my engine to that.
 
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Originally Posted By: Rand
Starting tbn and tbn retention are 2 different things. I'd uoa at 5000miles to see how it goes in your engine. +1 if you get a TAN on the uoa
+1 grin. Whimsey
 
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Originally Posted By: Rand
Starting tbn and tbn retention are 2 different things. I'd uoa at 5000miles to see how it goes in your engine. +1 if you get a TAN on the uoa
I have to agree regarding the TBN retention. Take Amsoil AEL Euro Formula 5w30 for example. Starting TBN is 5.8. After 6,000 miles the oil has 3.6 TBN. I'm sure it could easily make it to 10k. Besides, engines that require 10k OCIs also have like 7-8 quarts of oil in the sump, so there's A LOT of oil in there, even if the starting TBN is low.
 

The Critic

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Originally Posted By: Artem
Besides, engines that require 10k OCIs also have like 7-8 quarts of oil in the sump, so there's A LOT of oil in there, even if the starting TBN is low.
My Prius holds 4.4 quarts. I remember that a former member, Tooslick, once said that an oil's detergency is not linear. Once the TBN drops below 4 (or 2, depending on the testing method), the detergency is greatly reduced and the amount of deposits being left behind will increase, which will decrease the life of the next fill. I guess the analogy is equivalent to a very soapy kitchen sponge vs one that only has a small amount of soap left-- which one will clean a dish better?
 
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Originally Posted By: The Critic
I remember that a former member, Tooslick, once said that an oil's detergency is not linear. Once the TBN drops below 4 (or 2, depending on the testing method), the detergency is greatly reduced and the amount of deposits being left behind will increase, which will decrease the life of the next fill.
That's why you need to do the TAN test as well. If TAN exceeds TBN, the oil is shot.
 
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Originally Posted By: JHZR2
Low saps in ga$$ers is incompatible wth US gasoline because of the sulfur content. If we had 15ppm ULSG like we have ULSD, it would be OK. I validated this running M1 ESP 5w-30 that met he current VW spec in our VW.
How many miles did the ESP hold up? Do you have a UOA on the ESP? Thanks
 
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Originally Posted By: Artem
Originally Posted By: Rand
Starting tbn and tbn retention are 2 different things. I'd uoa at 5000miles to see how it goes in your engine. +1 if you get a TAN on the uoa
I have to agree regarding the TBN retention. Take Amsoil AEL Euro Formula 5w30 for example. Starting TBN is 5.8. After 6,000 miles the oil has 3.6 TBN. I'm sure it could easily make it to 10k. Besides, engines that require 10k OCIs also have like 7-8 quarts of oil in the sump, so there's A LOT of oil in there, even if the starting TBN is low.
Important point taken from this is that it's good to know the VOA and UOA to compare percentage loss of TBN vs. rate of increase of TAN.
 

The Critic

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Originally Posted By: Quattro Pete
Originally Posted By: The Critic
I remember that a former member, Tooslick, once said that an oil's detergency is not linear. Once the TBN drops below 4 (or 2, depending on the testing method), the detergency is greatly reduced and the amount of deposits being left behind will increase, which will decrease the life of the next fill.
That's why you need to do the TAN test as well. If TAN exceeds TBN, the oil is shot.
I have raised this point once before. However, by that standard, many conventional oils would be shot by about 3500 miles-- according to the lubrizol study I posted a while back. There has to be more to that recommendation.
 
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Originally Posted By: Quattro Pete
That's why you need to do the TAN test as well. If TAN exceeds TBN, the oil is shot.
I think it's more complicated than this. I've noticed that most of the analytical labs don't normally offer TAN as part of their analysis packages for motor oils. TAN is normally offered for industrial equipment. Plus, some synthetic motor oils have a significant starting TAN.
 
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I know you guys will think I am an idiot but what is TBN Also this forum desperately needs a acronym chart (unless there is ine then please call me names and link me) I have never seen so many I think I spend have my time reading these threads trying to solve the acronyms TIA, Anthony
 
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Originally Posted By: The Critic
Originally Posted By: Quattro Pete
Originally Posted By: The Critic
I remember that a former member, Tooslick, once said that an oil's detergency is not linear. Once the TBN drops below 4 (or 2, depending on the testing method), the detergency is greatly reduced and the amount of deposits being left behind will increase, which will decrease the life of the next fill.
That's why you need to do the TAN test as well. If TAN exceeds TBN, the oil is shot.
I have raised this point once before. However, by that standard, many conventional oils would be shot by about 3500 miles-- according to the lubrizol study I posted a while back. There has to be more to that recommendation.
Read Here: TBN And Here: TAN vs TBN The best info I've seen so far is that the optimal minimum TBN point is no less than 33 percent of the starting number. That would be a bit under 2 for a 6 TBN oil (tested in the same manner).
 
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Originally Posted By: The Critic
I have raised this point once before. However, by that standard, many conventional oils would be shot by about 3500 miles-- according to the lubrizol study I posted a while back.
Well, maybe Jiffy Lube was right after all to suggest those 3K oil changes. LOL Not sure about conventional, but on my last UOA on GC, after 10K miles, TAN was approaching TBN. Even though TBN was still at 4.3 (old testing method), Wearcheck recommended the oil be changed. Not saying they absolutely know what they're doing. I'm just throwing out an example.
 
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