This engine will definitely have some serious problems.
I think a zero tbn would be hard to get unless you did something drastic like this.
If you keep the oil topped up on the dipstick, you would always be boosting tbn each time you add oil.
Sometimes, I think we make too much of it. Just because you are showing tbn in range, doesn't mean your oil is still fine.
In other words the TBN analysis is meaningless
since a reading of 0.00 will likely cause or give you bad reading in your UOA Am I right?
Viscosity,wear metal,and contamination are the most important data.
One can assume that if the wear metal are within an acceptable level, that the oil remains in the original viscosity, and if the oxidation, nitration, and sulfation aren't out of range at the end of the OCI that the oil was doing the job or wasn't used for a too long period of time.
Am I right ??
I think you are right, but I don't think TBN is meaningless. It can give you a good feel of whether and how much longer you can extend the oci. It will also indicate that maybe you are pushing the envelope.
I probably won't get it in the future, because I'm not trying to figure out how long to extend drain intervals.
It's value is only in determining extended drains, imho.