In Reply to: Oil tested after 10 years use. posted by Larry Holbrook on December 10, 2018 at 11:31:47:
When I was in the navy 50 years ago we did not change oil-in fact we were taught in A school that oil never wore out it just got dirty. On board our boat all lube oil was cleaned using centrifuges made by DeLaval-the oil was pumped upward through the unit and the contaminates thrown off at high RPM onto a series of discs like stacked records. The oil exited at the top and was returned clean to the lube oil tank. This primarily served our four GMC 16 cylinder diesels in the forward and after engine rooms (two in each). It was always a dirty job cleaning the discs afterward.
I believe it was the same in the surface navy, except for small boats.