Forum Discussion

wagonmaster2's avatar
wagonmaster2
Explorer
Oct 15, 2015

Shelf life of DEF fluid

I've read that DEF fluid doesn't have a very long shelf life so I was wondering about the fluid that's left in the coach tank during winter storage. Will it be okay for 3-5 months of storage or does the tank have to be drained somehow and fresh added the next spring?

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  • Winged_One's avatar
    Winged_One
    Explorer
    Oct 15, 2015
    I have stored my truck for the last 2 winters (about 5 to 6 months each). No issues with DEF.
  • NinerBikes's avatar
    NinerBikes
    Explorer
    Oct 15, 2015
    It should keep at least 2 years. I'd be more concerned about the temperature that it freezes at, and will it split the tank it's stored in, if it expands during freezing, since it is 68% distilled water, 32% urea.

    If you are worried, buy a 2.5 gallon tank or two at walmart, when the low warning light comes on, after burning off all the older adblue.

    BTW, what does the owners manual say for the engine manufacturer, for recommendations?

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