Jolene said..
I have never seen oil stay clean, Oil that comes straight out the container can be considered dirty as it could be cleaned further. The condition of the engine will determine how quick the oil gets contaminated. To use the amount of dirt you have in the oil as a guide to having the right oil is BS.
The better the health of the engine and the better the quality of parts in the engine,, the oil will stay cleaner for longer
Every diesel (land or sea) I've ever had the oil was BLACK almost instantly, until this boat, a 25-30year old Buhk(changed somewhere in the 90's) the oil was like new when I checked on purchase, checked again after a couple dozen hours... still super clean, 1 year on, maybe 80-90 hours later, multiple checked, level on dip stick has moved about 1/2mm, never topped up, and oil has only just very slightly discoloured, not enough to leave a stain on your hand. Was worried at first thinking it wasn't getting pumped around, however after replacing oil pressure switch, new temp gauge... doesn't get hot or ever low oil pressure ...
Either the donk has almost no hours on it, or it's just a super clean running engine.
Will be interested to see all the oil once I suck it all out..
All good I guess