It seems that many here look at remaining TBN as the ONLY metric for lifespan of an oil change. However, it seems that it would be just as important to know if you have exceeded the capacity of the dispersants, have exhausted the AW or EP additives, ect. The TBN is only a measure of buffering capacity for acids. Is TBN REALLY the weak link? Is the half-life of the other additive much, much longer than TBN? Does soot, particle count, and dissolved varnish just not matter in the average application?
TBN as the only useful metric?
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Originally Posted By: GMorg
However, it seems that it would be just as important to know if you have exceeded the capacity of the dispersants, have exhausted the AW or EP additives, ect.
Well, sure, but can you get all that info from a $20 UOA? We focus on what's given to us.
However, it seems that it would be just as important to know if you have exceeded the capacity of the dispersants, have exhausted the AW or EP additives, ect.
Well, sure, but can you get all that info from a $20 UOA? We focus on what's given to us.
Actually the up spike of metal is the only useful metric. TBN is simply a possible early warning. Ive seen oil run below 1.0 for thousands of miles with no issue and Ive seen a major increase in metal at well above 2.0...
With that said I dont think I would worry to much with a 10.0 TBN nor would I plan a 6,000 mile trip on oil with a 0.0 TBN.
With that said I dont think I would worry to much with a 10.0 TBN nor would I plan a 6,000 mile trip on oil with a 0.0 TBN.
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I think TBN is used as a surrogate for other additives.
WRT AW, EP and dispersants, who knows?
Some members here do, and maybe they'll chime in.
You might say that if the oil shows some remaining TBN, and viscosity hasn't declined to some ridiculous level, and wear metals look reasonable, then the oil has done its job for the time in service it saw.
UOAs are fun, and I think they'll show anything scary (other than sludge or an impending mechanical failure, like a failing rod), but there is so much that we don't see in VOAs/UOAs.
WRT AW, EP and dispersants, who knows?
Some members here do, and maybe they'll chime in.
You might say that if the oil shows some remaining TBN, and viscosity hasn't declined to some ridiculous level, and wear metals look reasonable, then the oil has done its job for the time in service it saw.
UOAs are fun, and I think they'll show anything scary (other than sludge or an impending mechanical failure, like a failing rod), but there is so much that we don't see in VOAs/UOAs.
Originally Posted By: Gene K
Actually the up spike of metal is the only useful metric. TBN is simply a possible early warning. Ive seen oil run below 1.0 for thousands of miles with no issue and Ive seen a major increase in metal at well above 2.0...
With that said I dont think I would worry to much with a 10.0 TBN nor would I plan a 6,000 mile trip on oil with a 0.0 TBN.
I think silicon is also very useful. As long as one factors the legitimate causes of high silicon into the mix.
Polaris/OAI gives nitration and oxidation. I think they are useful.
Actually the up spike of metal is the only useful metric. TBN is simply a possible early warning. Ive seen oil run below 1.0 for thousands of miles with no issue and Ive seen a major increase in metal at well above 2.0...
With that said I dont think I would worry to much with a 10.0 TBN nor would I plan a 6,000 mile trip on oil with a 0.0 TBN.
I think silicon is also very useful. As long as one factors the legitimate causes of high silicon into the mix.
Polaris/OAI gives nitration and oxidation. I think they are useful.
Originally Posted By: Donald
Originally Posted By: Gene K
Actually the up spike of metal is the only useful metric. TBN is simply a possible early warning. Ive seen oil run below 1.0 for thousands of miles with no issue and Ive seen a major increase in metal at well above 2.0...
With that said I dont think I would worry to much with a 10.0 TBN nor would I plan a 6,000 mile trip on oil with a 0.0 TBN.
I think silicon is also very useful. As long as one factors the legitimate causes of high silicon into the mix.
Polaris/OAI gives nitration and oxidation. I think they are useful.
I should plead guilty to oversimplifying. I was pointing out that TBN is simply an indicator no the end all be all of oil analysis
Originally Posted By: Gene K
Actually the up spike of metal is the only useful metric. TBN is simply a possible early warning. Ive seen oil run below 1.0 for thousands of miles with no issue and Ive seen a major increase in metal at well above 2.0...
With that said I dont think I would worry to much with a 10.0 TBN nor would I plan a 6,000 mile trip on oil with a 0.0 TBN.
I think silicon is also very useful. As long as one factors the legitimate causes of high silicon into the mix.
Polaris/OAI gives nitration and oxidation. I think they are useful.
I should plead guilty to oversimplifying. I was pointing out that TBN is simply an indicator no the end all be all of oil analysis
ALL the numbers together in a treading fashion (ie more than a single UOA) is what is needed. Then once you know how the engine is doing you can make some decisions on what/how to run.
TBN is useful because it is more data.
Bill
TBN is useful because it is more data.
Bill
TBN vs TAN is relevant too, but when it comes to different fuel types everything gets wonky.
Originally Posted By: Donald
Originally Posted By: Gene K
Actually the up spike of metal is the only useful metric. TBN is simply a possible early warning. Ive seen oil run below 1.0 for thousands of miles with no issue and Ive seen a major increase in metal at well above 2.0...
With that said I dont think I would worry to much with a 10.0 TBN nor would I plan a 6,000 mile trip on oil with a 0.0 TBN.
I think silicon is also very useful. As long as one factors the legitimate causes of high silicon into the mix.
Polaris/OAI gives nitration and oxidation. I think they are useful.
I bought a series of 10 oil analyses from Polaris for $200 which includes TBN, TAN, Oxidation, and Nitration readings. This first that I had done on Red Line oil out of my Camaro showed excessively high oxidation, which Polaris flagged as "You must change the oil immediately". I did not get all bent out of shape over the oxidation number, because POE oils do show high oxidation numbers, even when new. I sent them a virgin oil sample of RL 5w30 to get a baseline on oxidation.
Originally Posted By: Gene K
Actually the up spike of metal is the only useful metric. TBN is simply a possible early warning. Ive seen oil run below 1.0 for thousands of miles with no issue and Ive seen a major increase in metal at well above 2.0...
With that said I dont think I would worry to much with a 10.0 TBN nor would I plan a 6,000 mile trip on oil with a 0.0 TBN.
I think silicon is also very useful. As long as one factors the legitimate causes of high silicon into the mix.
Polaris/OAI gives nitration and oxidation. I think they are useful.
I bought a series of 10 oil analyses from Polaris for $200 which includes TBN, TAN, Oxidation, and Nitration readings. This first that I had done on Red Line oil out of my Camaro showed excessively high oxidation, which Polaris flagged as "You must change the oil immediately". I did not get all bent out of shape over the oxidation number, because POE oils do show high oxidation numbers, even when new. I sent them a virgin oil sample of RL 5w30 to get a baseline on oxidation.
Here's an interesting thread on TBN and TAN - https://bobistheoilguy.com/forums/ubbthreads.php?ubb=showflat&Number=1675009
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