Winter Storage......To change or not to change oil????

[zell66]

PLEASE don't chastise me but a real question. Is it better to change oil before winter storage (central Wisconsin) or do it in Spring and why?

 

[GA_Boater]

One school of thought says a Fall oil change drains combustion by-products and blow-by from the motor, which could be acetic.

Another says wait 'til Spring and start fresh.

One more says to follow the manufacturers recommendation.


Take your pick. Personally I used the Fall change when I still had an I/O.

 

[cwburkeva]

In my experience, changing in the fall. Less to do in the spring, but I could be off base.

 

[Scott Danforth]

Change in fall as part of your winterization process as oil becomes acidic

 

[mklearl]

Fall because that's what the manual says to do.

 

[tpenfield]

Spring, because I usually have more than enough to do in the Fall.

 

[BRICH1260]

I`ve asked the same thing before and have always ben told that it`s best to do in the spring as the oil becomes toxic if left in the pan with the previous seasons by products. So I have always changed mine in the spring.

 

[ericga]

I change mine in fall after a 1h cruise to boat storage. I like to know the oil condition for the off-season (if any water/fuel contamination, metal shavings etc..).

 

[Scott Danforth]

If you dont runn it after changing it, oil wont become toxic from combustion byproducts

 

[zell66]

OK so makes sence for fall change. Now pro's and con's for motor oil or synthetic?

 

[ericga]

What engine you have?

 

[zell66]

4.3l

 

[jeffnick]

I put her to bed with fresh oil. I like to know there's no water in my engine or outdrive oil that might freeze during the winter.
I'm not a fan of extended drain intervals so I can't see any benefit to synthetic.

 

[jimmbo]

As mentioned used oil may become acidic. And acids love to eat metal, and they will do a number on the softer metals in bearings. But it is your engine so do what you want.

 

[ericga]

Use synthetic if the engine is used in extreme conditions where more resistance to thermal breakdown or oxidation is needed. Otherwise a quality mineral marine oil such as the QuickSilver 25w40 will be more than enough.

 

[bruceb58]

Mercruiser and Volvo recommend semi-synthetic or synthetic in their currently offered engines.

 

[zell66]

found my manual pdf in this forum. recommends 20w50, The engine is a 1996 so 20 yrs old and no idea of hours on her. What is best for this age of motor?

 

[LegacyT]

I always change the oil and filter at the end of the season right before winter layup. I'll dedicate 3 or so hours to do that, going for a quick run to warm the oil to change out. Afterwards going for another 10 minute ride to circulate the fresh oil throughout the engine. Once on the trailer - but still on the water, I'll disconnect the fuel line and run the engine while fogging until the motor dies from fuel starvation (to avoid fuel going bad and gumming up in the carb). After it's completely out of the water I'll pull the block and manifold drain plugs and drain all the water from the engine while towing for storage and carry on with the rest of the winterization at storage. As for oil I use She'll rotella 15w-40, it's cheap, has good reviews and readily available. I boat 30-50 hours so conventional oil is fine for me. If I boated more hours per season or used the boat in very cold temperatures then I'd consider synthetic..

 

[ericga]

People will perceive an engine to be better or more technology advanced because synthetic is recommended and there is nothing wrong using something that offer even more protection than what's truly needed. If the manufacturer is specific about using synthetic than its a different story and by all means use synthetic.

Engine oil is not where you should go cheap for saving few bucks. Trade that tenderloin steak for a burger once in the boating season and apply the savings on a good quality marine engine oil. Go synthetic if you want the extra peace of mind or if the engine is used in extreme conditions (you might need to have extra burgers ).

As oil debate can easily get out of control I suggest an interesting reading on marine oil certification below:

https://www.nmma.org/certification/oil