Forum Discussion

two_travelers's avatar
two_travelers
Explorer
Oct 22, 2023

DEF fluid expiration?

We have a 2023 Winnebago View on the Sprinter chassis. Currently have about 1/2 tank of DEF and plan to top off before storing for the winter. I have some DEF in the basement with a manufacture date of May. Is it safe to use this or should I buy fresh? We will likely use the coach again in March next year. From what I've read it might be OK but would like some real world opinions.
Class C
  • Grit_dog's avatar
    Grit_dog
    Navigator
    Oct 22, 2023
    It’s not gasoline, so the topping off theory (also flawed when considering gasoline) does not apply.
  • enblethen's avatar
    enblethen
    Nomad
    Oct 22, 2023
    From DEF facts

    16. What is the shelf life of DEF?
    If the DEF is stored at ambient temperatures of 75 F with no major periods of exposure to heat over 86 F then the batch of DEF will last roughly two years. If a package of DEF is exposed to periods of heating the fluid will last approximately one year.
  • Trackrig's avatar
    Trackrig
    Explorer II
    Oct 22, 2023
    All sorts of people are going to leave it sitting in their equipment that will sit idle for at least the winter. Farmers, dirt people, truckers, etc.

    Bill

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