I hit return befor I finished thinking.
daman: I was passing thru Sandusky, SIL/BIL farm just north of Ubly (they are part of the Van Erp clan in your neck of the woods)
I did not bother with the TBN - I'm cheap and I was primarily interested in the ZDDP, I follow a 3,6,9 oil change interval (ie. xx3,333, xx6,666 and xx9,999 miles) easly to keep up w/ oil changes when the odometer is staring me in the face. So with my limited understaning of what the TBN represents, I suspect (hope) that it is not of great importance to me. Both of my vehicles that are currently using this oil are gasoline engines w/ flat tappet cam/lifters