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