Run a Frantz filter, change it once a year, and top off to the full mark on the dipstick whatever oil is lost during the filter change. The 855 Cummins engines we ran that way had 50K miles or more without a full oil change. Oil analysis by an independent testing lab after every filter change confirmed that the oil was still within limits for continued use.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!