i have seen a variety of opinions on bitog regarding total base number as an indicator of when to change your oil; many wise drivers like to be cautious and not go much below 3.0; of course application and operating conditions are always factors; i am considering going below the blackstone threshold of 1.0; my thinking is that since i drive 250+ freeway miles a day, every day, there is plenty enough high temperature driving to burn off the acids accumulated in my oil during the normal process of combustion; the other components of the additive package in the oil will still be there to keep my engine clean; any comments are appreciated.
tbn and oci
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I would not take TBN below 1.0 on Blackstone's test. What are you trying to accomplish by doing so?
My understanding of sump chemistry is fairly limited but I'm always open to learn more. How, exactly, do acids 'burn off'? Fuel & water can be evaporated but my understanding is that acids can only be neutralized by the base capability of the oil itself. Once that is exhausted (i.e., when your TBN is low and your TAN is rising) nothing else will stop it from happening aside from replenishing the additives in the oil or changing it.
My understanding of sump chemistry is fairly limited but I'm always open to learn more. How, exactly, do acids 'burn off'? Fuel & water can be evaporated but my understanding is that acids can only be neutralized by the base capability of the oil itself. Once that is exhausted (i.e., when your TBN is low and your TAN is rising) nothing else will stop it from happening aside from replenishing the additives in the oil or changing it.
The relationship between TAN and TBN is important too.
The 1.0 value is just a single recommendation and it's likely that the oil should've been changed before that due to excess acid buildup.
The 1.0 value is just a single recommendation and it's likely that the oil should've been changed before that due to excess acid buildup.
The holy grail of leftover TBN is 1.0 on Blackstone's scale. Everyone is either aiming for it or is afraid to get near it because they think the oil will just stop working all the sudden.
I suggest you just aim for the 1.0 mark. That will leave you with LOW TBN additives, as Blackstone always says, which is where the oil is no longer suitable for SAFE use anymore. Dump the oil at that point and move on with your life. It doesn't make any sense to push it further for the sake of what, getting your money's worth outta the last ounce of TBN left? Come on, an oil change these days is basically FAR (Free After Rebate) and has been for several months now. I, like many have stocked up on said oil deals and can afford to change the oil every 3k if i want because it cost me about $1 total.
Oil is cheap, engines are not. I wouldn't risk it if i were you.
Also, everyone has different opinions because everyone uses different labs, which have different scales of measurement, therefor the recommendations are different. I suggest you stick to one lab and follow their recommendations with hopes that they know what they're talking about.
I suggest you just aim for the 1.0 mark. That will leave you with LOW TBN additives, as Blackstone always says, which is where the oil is no longer suitable for SAFE use anymore. Dump the oil at that point and move on with your life. It doesn't make any sense to push it further for the sake of what, getting your money's worth outta the last ounce of TBN left? Come on, an oil change these days is basically FAR (Free After Rebate) and has been for several months now. I, like many have stocked up on said oil deals and can afford to change the oil every 3k if i want because it cost me about $1 total.
Oil is cheap, engines are not. I wouldn't risk it if i were you.
Also, everyone has different opinions because everyone uses different labs, which have different scales of measurement, therefor the recommendations are different. I suggest you stick to one lab and follow their recommendations with hopes that they know what they're talking about.
Heat or highway driving evaporates water, those conditions do not "burn off the acids".
TBN is just one of several factors determining the acceptable OCI for your vehicle. As previously mentioned the relationship of TBN vs TAN is important, but so also is your contaminants levels, and additive package results. While running at highway speeds as you are many reduce the accumulation of acids due to little water/fuel contamination and therefore increase your TBN retention.
I guess I don't understand the reasoning behind dropping below the TBN of 1.0? What OCI are you currently running? Which Oil? How do you other UOA factors look (is everything very nice, it's just TBN that is an issue? - if that's the case then maybe you need to find another oil that meets your needs and has better TBN retention.)
I guess I don't understand the reasoning behind dropping below the TBN of 1.0? What OCI are you currently running? Which Oil? How do you other UOA factors look (is everything very nice, it's just TBN that is an issue? - if that's the case then maybe you need to find another oil that meets your needs and has better TBN retention.)
thank you for the common sense and informed opinions; i definitely misspoke in referencing "acid burn off;" i was thinking of the evaporation of acid- causing moisture in freeway driving; i'm using premium synthetic oil and am trying to get full value out of it; i think somewhere around 1.0 tbn and looking at the other numbers will be my cut off point; i expect good tbn retention with my conditions.
You live in an area without extremes of temperature and you do an ideal sort of driving for oil life.
What kind of OCI are you running now?
Have you done a UOA at, say, 10K?
I think 2.0 is a safe condemnation point for the oil, since this will always give you some cushion for unusual conditions or an unusually low starting TBN in a given batch of oil.
It may also be that you can select an oil that will allow longer drains than the one that you're using.
Yeah, I know that the oil has OMG VI, but how important is that in the climate you operate in and the way in which you use the car?
If I used a car as you so, I'd consider Amsoil SSO and do a couple of UOAs at 15K and maybe 20K.
The way you use your car, you could probably do 25K changes on a sufficiently robust oil.
What kind of OCI are you running now?
Have you done a UOA at, say, 10K?
I think 2.0 is a safe condemnation point for the oil, since this will always give you some cushion for unusual conditions or an unusually low starting TBN in a given batch of oil.
It may also be that you can select an oil that will allow longer drains than the one that you're using.
Yeah, I know that the oil has OMG VI, but how important is that in the climate you operate in and the way in which you use the car?
If I used a car as you so, I'd consider Amsoil SSO and do a couple of UOAs at 15K and maybe 20K.
The way you use your car, you could probably do 25K changes on a sufficiently robust oil.
i just started using the sustina- 5k miles in 3 weeks! the uoa's will start happening in a couple of weeks and i will be sure to post them; it's starting to occur to me that my driving conditions are very unsevere; the amsoil signature series interests me; i will definitely consider it- and 25k oci; start up wear concerns me as does dealing with california smog laws.
The sustina oil you are using is an excellent oil. If it was me, I would keep using it for a couple of months, doing UOA and see how far you can comfortably extend (as you have mentioned you are driving in an ideal instance for long service life). I would do that before changing to amsoil. (not that amsoil is bad, but you should get pretty good extended mileage life out of the sustina).
Just change sooner why does changing motor oil sound like such a HUGE JOB at times WOW!
Originally Posted By: ottotheclown
Just change sooner why does changing motor oil sound like such a HUGE JOB at times WOW!
Why waste perfectly good oil by changing it early? The OP wants to use the oil to its fullest, conserving our natural resources as well as spending less time laying under the car. I fully support extended OCIs with UOAs to back it up.
Just change sooner why does changing motor oil sound like such a HUGE JOB at times WOW!
Why waste perfectly good oil by changing it early? The OP wants to use the oil to its fullest, conserving our natural resources as well as spending less time laying under the car. I fully support extended OCIs with UOAs to back it up.
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