Between-overhaul mileage of a well maintained RV gas engine?

Lets make this analogy. If you only got off your sofa once or twice a year your moving parts would not last very long. Run your engine until it reaches operating temps even when stored on a regular basis, and change oil and filters per manufacturer specs and your engine should enjoy a long healthy life. Sitting unused is no good for moving parts. Including both yours and the the MH.