Engine without Oil for Winter Layup

[deltasig]

For years I changed the engine oil and filter as soon as the boat is hauled out for the winter and the engine still warm. After the start of the new season, I would not think about the engine oil except to check the level.

An ex-Navy engineer suggested that the fresh oil sitting in the engine for close to 7 months has lost most of its properties and that one needs to change it again before launching.

The option to change the oil, again, is out of the question due to cost ($100 for the 2 oil changes...just for the oil).

Does one leave the old (100-150 hrs) oil and filter for the winter and change it before launching or remove it and leave the engine without oil for the winter?.

I understand that leaving the old oil in implies that all and any impurities in it (carbon, sulfuric acid etc) stay in the engine; so removing it is a good idea.
Leaving the engine without oil may have its own drawbacks.

Any suggestions/thoughts? Thank you

[marc2012]

I would not leave it dry.marc

[Ex-Calif]

If it worries you much.

Drain it - don't fill it.

Pull the plugs and squirt some fresh oil into the cylinders. Not enough to create a hydraulic lock. Rotate the engine a few times.

Don't forget to fill it at relaunch.

[Mark Zarley]

People that really care about their engines, will not only leave new oil in them , but will bar(assuming the batteries have been disconnected or removed) them over every couple of months just to keep an oil film on the bearing surfaces. I don't think oil can "go bad" have not noticed any "use by date", I don't see much difference in storing the oil in your engine or it sitting in a 55 gal drum. You mention you drain your oil after haulout. Does this mean you do not start it up after changing, which would flush out and dilute any of the old oil and recoat your internals. Just a thought.