Interesting reading and at 25 thousand miles???
Yup ...
I didn't drain and totally change out the oil until that sump had over
51,000 miles on it .... and it was likely still good then (I have a sample from that drain I still haven't gotten around to sending in :confused2
Blackstone's report forms make it a little confusing - it's the same oil sump from mile 135,283 to mile 160,259 on the odometer and the makeup oil listed is a
total up to that time on the last two UOA's,
not cumulative (IOW, 5.25 total quarts over 24,976 miles)
Consulting my maintenance log, I see that the entire sump (around 10.5 quarts) was eventually changed out at 186,657 .... so 186,657 minus 135,283 = 51,371 miles on the sump before changing ....
What type bypass filter are you using??
A Motor Guard M-30, modified by Ralph Woods of Texas .... essentially it's a TP filter (toilet paper - I mostly used Scott 1000

) .... similar to a Frantz ....
I usually changed the filter every 3K to 5K miles (roll of TP is less than a buck) and added maybe a 1/4 to 1/2 quart of make up oil.
Right now the bypass filter is off the truck - I got tired of changing the filter so often (I'm lazy and I run a lot of miles) ....
I have a centrifuge (Spinner) filter I haven't gotten around to installing yet .... should require less servicing.
I have not added one to this engine yet, as i do still have factory warranty... So as that is up,,, then i plan on adding the second filter..
Worthwhile investment if you run a lot of miles or hours IMHO ....