Eric--- In many decades of dealing with engines--- auto, plane, rail, and boat--- I have NEVER heard or read that clean oil " goes bad" just sitting there. If it did, all oil sold would have a sell-by or use-by date on it. I think you've been taken in by an urban myth.
A different oil question
- Thread starter mattkab
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psneeld
Guru
Plus as I posted before...many places buy bulk oil dispensed to 100-500 gallon tanks for fleet use....It sits there for many months .
The company that I work for that has an assistance towing fleet, small tug/barge fleet, numerous tractor trailer and dumptruck rigs, a dozen diesel pickups and dozens of small diesel gensets, pumps, light units, etc...etc.
They all get the same bulk 15W40 oil...and during the winter when things get slow....hundreds of those gallons sit until needed in the spring turnover.
Millions of miles, hundreds of thousands of op hours...no oil related issues.
Nomad Willy
Guru
Marin,
My source or sources may not have been marine. I told my dad that a long time ago and I usually didn't tell dad something I wasn't sure about. Perhaps I shouldn't have mentioned it. When you change oil the new oil gets mixed w a bit of the old oil so it' instantly slightly contaminated. Oil in 2 strokes mixed w the fuel goes bad. Fuel in a car goes bad. People after the shy part of 100 years go bad. Glass goes bad given enough time. Organic stuff grows in fuel oil. I'm say'in the odds are that lube oil goes bad in the winter given cold temps and humidity that can't be avoided. But I'm not really sure.
Me changing oil really often (especially skipping filters often) is very easy and only takes a few quarts whereas w two LAehmans or similar it's not such a little deal.
My source or sources may not have been marine. I told my dad that a long time ago and I usually didn't tell dad something I wasn't sure about. Perhaps I shouldn't have mentioned it. When you change oil the new oil gets mixed w a bit of the old oil so it' instantly slightly contaminated. Oil in 2 strokes mixed w the fuel goes bad. Fuel in a car goes bad. People after the shy part of 100 years go bad. Glass goes bad given enough time. Organic stuff grows in fuel oil. I'm say'in the odds are that lube oil goes bad in the winter given cold temps and humidity that can't be avoided. But I'm not really sure.
Me changing oil really often (especially skipping filters often) is very easy and only takes a few quarts whereas w two LAehmans or similar it's not such a little deal.
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Fuel over time is another story, particularly today's fuel. But clean/new lube oil? Based on experience and everything I have learned I would say that on this one, Eric, you are 100% absolutely dead wrong.
psneeld
Guru
Engine/Motor Oils and Transmission Oils [FONT=Interstate Light,Interstate Light][FONT=Interstate Light,Interstate Light]Although these oils contain high additive contents, they are extremely stable. They may be stored for 5 years under protected conditions without any significant deterioration in performance. However, as the industry is always developing new specifications these oils may be out of date by the time they are fully used.
http://www.penriteoil.com.au/FactSheets/Fact%20Sheet%20-%20Shelf%20Life%20of%20Lubricating%20Oils.pdf
3-5 years seems to be the concensus....
[/FONT][/FONT]
Nomad Willy
Guru
Do you lads consider the cold and a bit damp crankcase coated w contaminated oil on a diesel engine in a boat usually immersed in sea water "under protected conditions"?
I sure don't.
I sure don't.
You seem to be talking about dirty oil, and of course that is contaminated and the contamination may well cause the oil to deteriorate over time.
But that's not what we've been talking about. We've been talking about new oil put in a boat immediately prior to the boat's being laid up for the season. So the oil is not contaminated. As such the clean oil does not deteriorate just sitting there in the engine, or a can, or a jug, or a barrel, or a storage tank. Clean is clean and throwing out new, clean oil at the end of four months or so and replacing it with equally new, clean oil seems sort of stupid to me.
FF
Guru
- Joined
- Oct 12, 2007
- Messages
- 22,552
"In fact a case could be made for changing the filter once halfway through the season keeping the same oil, in view of the fact that the solid contaminants are filtered out in the filter,"
However much of the engine wear is not caused by the coarse chunks the std oil filter removes , but by the "fines" (tiny as valve grinding compound) that freely circulate in the oil.
Solution ,secondary centrifugal filter to spin them out, by pass filter that is better at removing the fines , (but use a filter not a roll of toilet paper) , OR , simply change the oil.
All modern oil is detergent oil so only change the oil after a long hard run so the chemicals have time and temperature to loosen the collected grunge and capture it in the oil.
However much of the engine wear is not caused by the coarse chunks the std oil filter removes , but by the "fines" (tiny as valve grinding compound) that freely circulate in the oil.
Solution ,secondary centrifugal filter to spin them out, by pass filter that is better at removing the fines , (but use a filter not a roll of toilet paper) , OR , simply change the oil.
All modern oil is detergent oil so only change the oil after a long hard run so the chemicals have time and temperature to loosen the collected grunge and capture it in the oil.
