There was a very thoughtful discussion on diesel pusher oil usage on RV.net recentely.
http://www.rv.net/forum/index.cfm/fu...d/23897924.cfm
The consensus seems to be that each engine has a sweet spot. If you overfill beyond that sweet spot the engine will throw off the oil. Once it hits its sweet spot the oil usage virtually stops. I have noticed that when I insist on filling mine up to the full mark it throws off the oil until it gets down 2 quarts, then it seems stop for long time. Would be interested others thoughts after you read the discussion (see the link in parenthesis above) as well as your experiences with this issue.