Seeking opinions at my own peril. How often (hours) are you changing the oil in your diesel motor? I'm running an Yanmar 3JH2E and have been changing the oil at 50 hr intervals. Seems excessive. The operators manual calls for 1st change at 50 hrs and 150 hrs thereafter. Granted, its a lot to get 50 hrs in a sailing season unless long trips are involved. I would change the oil before winter lay up regardless of hours. Its August, I've got just over 50 hours on this oil, plan to haul in October ... seems like a waste to put a couple dozen hours on fresh oil then change again for winter storage.