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VinnyP's avatar
VinnyP
Explorer
Jul 07, 2020

DEF how old is too old?

I have an opened jug of DEF dated July 2019. Can't tell if that is a manufactured date or an expiration date. Any ideas? Or should I just breakdown, dump it and buy a fresh jug?
  • From what I've read, DEF gets "iffy" after 18-24 months. Is that date of July 2019 from a Blue DEF code? If so, it was actually made in July of 2018.
  • NRALIFR wrote:
    It’s probably OK, but you can get on Amazon and buy an inexpensive refractometer that will tell you if it still has the correct 32.5% urea. Some refractometers can also check multiple fluids, like antifreeze, windshield washer fluid, DEF, and battery acid.

    :):)


    And for only the cost of 2 NEW jugs of DEF or probably 6+ gallons at the pump you could buy a device to "check" it....
    How is this even a question or a thread?

    (BTW NRA, you're correct, but you just got over the OP's head, mechanically speaking. He's best off parting with an Alex Hamilton and a couple of G Dubs for some fresh DEF...)
  • VinnyP wrote:
    Any ideas? Or should I just breakdown, dump it and buy a fresh jug?


    Pheww, quite the quandry here. You have an expensive truck that presumably is worth alot of money becasue it's fairly new, diesel, and likely doesn't get driven much.
    Now you have a partial jug that you didn't manage to use in the last year or so and how long will that DEF sit in your truck?

    Bottom line don't be a cheap ___ and save yourself potential/likely future headaches at the expense of spending 10 whole dollars on your truck.
  • It’s probably OK, but you can get on Amazon and buy an inexpensive refractometer that will tell you if it still has the correct 32.5% urea. Some refractometers can also check multiple fluids, like antifreeze, windshield washer fluid, DEF, and battery acid.

    :):)
  • VinnyP wrote:
    I have an opened jug of DEF dated July 2019. Can't tell if that is a manufactured date or an expiration date. Any ideas? Or should I just breakdown, dump it and buy a fresh jug?

    IMO the risk reward ratio is not good
    $10 worth of def vs a huge repair bill if it goes bad in the tank
  • There is no solid answer.

    All sorts of conditions come into play like heat or cold or sealed or unsealed.

    "I" would not worry about it if it was sealed. But that's me.