Changing the oil during winterization

[jasmo123]

Hello,
I am asking for opinions on the recommendation of changing the oil during winterization. I have read during my other studies that oil, when it sits, looses its viscosity. So why would you not just leave the oil in the engine during the winter and change it before you start the next season? The oil just just sits in the engine until next year. Why wouldn't you want to get fresh oil when you are going to start using the boat? Instead of oil that has been sitting in the oilpan for about 6 months. Any comments or opinions on this subject is appreciated.
JASMO

 

[truckermatt]

Re: Changing the oil during winterization

well you change the oil in the fall, because oil absorbs water in the summer during usage and if there is any water(oil) in the engine over winter it can freeze and cause problems.....

Same with lower unit oil..

Oil stays on the shelf for 6 months sometimes before its in your engine...

 

[HT32BSX115]

Re: Changing the oil during winterization

Howdy,

I have read during my other studies that oil, when it sits, looses its viscosity.

Not true. (Total Barby Streye-Sand....AKA BS)

(I have even read that Shell indicates that the shelf life of Aeroshell W100 is 5 years or more. I have about 25 gallons of W100 and I plan to use it all in my 6A335B Franklin. Here's what another discussion board got back from Shell.

Subject: Oil shelf life
From: Tim Helton
Date: Thu Sep 28 13:18:23 2000
A while back there was a discussion about the shelf life of aviation oil....
I asked the folks at Aeroshell and today they responded:

------

Tim,

I asked our specialist in aviation about this question. He replied that
while the life of the oil on the shelf may be longer than two years
depending on the storage conditions, we prefer to stick with a two-year
shelf life for everyone's safety benefit. You might consider dumping the oil
in question, especially after seven years. For sure, it should not go into
an aircraft engine.

Thanks for your inquiry and interest in Shell products.

Ed

Ed Brown, for Shell lubricants
EBrown1@equilon.com
http://www.shell-lubricants.com )

It's clear that they are worried about liability (and of course, they're interested in selling oil)

So why would you not just leave the oil in the engine during the winter and change it before you start the next season?

Oil during use in an engine collects collects combustion products, water vapor and other contaminants. (which has VERY specific additives to keep those contaminants in suspension or mitigated) Some of those contaminants when combined with water vapor produce acids that can cause corrosion in an engine......

Other solid contaminants are collected and stopped by the filter..... which is exactly why you change the oil and filter.

It's FAR better to have fresh oil in the engine than contaminated oil sitting for 6mo to a year.

Changing the oil removes those contaminants.

In your drive, you don't necessasarily have to change it once a year (many don't) BUT you need to check the oil before "winter lay-up" (by draining a little from the bottom and carefully inspecting for water intrusion because you absolutely DO NOT want water sitting in the drive because if there's enough in there, it can freeze and "break" the drive as well as cause corrosion etc.


Cheers,


Rick


Oh, and by the way, the following info from ExxonMobil indicates a fairly LONG shelf life for their AV Oils....... up to 10 years!

http://www.exxonmobil.com/lubes/exxonmobil/emal/files/ShelfLife_techbulletin.pdf