% change in Add Pack = Oil Life Available?

[bruce381]

Buster Specro will show all the metals present even when they are depleted. They only go down due to additive fall out as sludge or varnish.
Thats why TBN is a good thing to look at even if CA is still high it has already nutralized asll the acid it can and that is why TBN is LOW.
bruce

 

[buster]

Mr. Wan brought up an interesting point, one that I've read before about additive packages depleting and that being an indicator of an oil's end.

However, I was looking back at two M1 reports, just as an example, and it doesn't seem to work out that way. For instance, in my brother's 10k M1 EP report, most of the additive package was still remaining. Only boron was depleted by more then 50%. ZDDP was only down about 25%. These are approxmations.

You would think that with %'g's that high, more TBN would be left in the oil. Does anyone think that Blackstone Labs TBN is just unreliable?

Example 1

Example 2

If that much add pack is still left, what enables the TBN to be only 2.2 in my brother's report? I would think their would be much more acid neutralization left with Ca still being 2100ppm.