Does oil have a life span in time?

[telliott]

So i recently made some changes and am only going to be putting about 400 miles a month on my pickup. At that rate, with a 5000 mile oil change interval, i would really only have to change my oil about once a year. My question is, will the oil lose its qualities with time rather than just miles? should i change my oil more often than just once a year? I know they use to say in gas engines to change every 3 months or 3k. I kinda just assumed they said that to make people buy more oil but maybe there is some truth?

 

[GOlsen]

From what I've read, at least in gas engines, the reason behind the time frame is that you get a little blow by, and the combustion gases react with the oil. This causes the oil to become slightly more acidic, which will slowly eat away at the metal. Now, is 3 months a little overkill? Probably. But if this is true, IMO, it's worth the money in the long run. Now a diesel engine on the other hand, may be a totally different story.

 

[JFaughn]

Change by oil analysis .
How much do you crank up your box's ?
With those injectors , I would think that your analysis would show high fuel & soot , if so frequent changes .
Also a bypass filter , or centrifuge to pull some of that out .

 

[telliott]

yeah, your probably right, but i try to keep the boxes down most of the time unless i'm feeling froggy.

 

[rbattelle]

According to Mobil, 5 years.
I think they're being conservative, since they also have to bear in mind the possibility to changing motor oil standards.

This site says 3 years.

Some people say "indefinite" if the container is unopened. If I were concerned, I'd contact the manufacturer of the specific oil I wanted to store and ask them.

Ryan

 

[steved]

Some people say "indefinite" if the container is unopened. If I were concerned, I'd contact the manufacturer of the specific oil I wanted to store and ask them.



Ryan

I would say yes if stored in a controlled temperature, but storing it where temps can varying quite a bit will cause the additives and paraffins to fall out of suspension...



Its a good habit to "shake well before use" any oil that has sat for a while.