Community Forums

RJEV · 05-31-2016, 04:59 PM

I bought Blue DEF at Walmart about 8 months ago and am not sure if it is too old to use. There are a series of numbers on the box and I wonder if there could be an expiration date in the series of numbers. Maybe like the mfg date on tires, weeks/years. Don't think so but thought I'd check.
Thanks,
RJ

windsorbill · 05-31-2016, 05:18 PM

as long as it's hasn't been opened and contaminated (dirt or ??), you should be fine.

I don't use it in the coach, but I do have a diesel F250 that uses it.

windsorbill · 05-31-2016, 05:21 PM

Forgot to mention, I found it at Franklin Truck Centers for $9.50 for 2 1/2 gallon jug. You can get it cheaper than that if you buy larger containers, but I can't justify that in the truck.

PanJH · 05-31-2016, 06:17 PM

I normally buy at the pump at Flying J, but sometimes pick up a box at Wally World. I noticed a few weeks ago that the new boxes in Wally World had legible expiration dates.

lanerd · 05-31-2016, 06:23 PM

I get it at Walmart for $7.88 for 2 1/2 gal. That's almost as cheap as truck stop pumps.

As mentioned, as long as it's sealed, it should be good for that 8 months easily.

Ron

nola69746702 · 05-31-2016, 08:31 PM

Just an FYI, Def does have a shelf life, it should not freeze and sunlight is also not good for it.

RJEV · 05-31-2016, 09:03 PM

Nola,
Do you know what the DEF shelf life is?

EV2 · 05-31-2016, 09:17 PM

At mid 70's and stored out of sunlight DEF has a shelf life of almost 4 years. And, even then it does not suddenly go bad. As it deteriorates slowly the system will dose heavier.

nola69746702 · 06-01-2016, 09:10 PM

I was told the shelf life is a year. I am a garage parts storekeeper and the vender said one year. Also not to let it freeze and not be in the sun.

lanerd · 06-02-2016, 06:26 PM

From a simple Google search:

Diesel Exhaust Fluid doesn’t degrade nearly as quickly as people assume. For example, at 86°F, DEF has a shelf life of a year. REMEMBER: Do not equate shelf life to spoiling like food, as DEF will not go bad. IT will lose some effectiveness, and the SCR will dose at a higher rate, but it won’t “go bad.” If maintained at a constant temperature, DEF manages to stay for several months. For example, at 74°F in Los Angeles, Diesel Exhaust Fluid has the shelf life of 44 months.

Hooligan · 06-02-2016, 08:35 PM

Here's a discussion of how to decode the date of manufacture of BlueDEF.
DEF Date Codes and API Certification

However, the last batch (April 2016) I got at Walmart had a plain language date of manufacture.
Also check the packaging, rumors? that some boxes were used, refilled with water and returned to stores. (knew a guy whose cousins uncle Fred talked to at a carwash)

Agaveguy · 06-02-2016, 11:52 PM

The SCR doesn't do the dosing, it's the selective catalyst which consumes the DEF , the DEF injector upstream of the SCR does the dosing. The DEF is very specifically blended at 37.5% urea concentration, if the ECM does not see the desired/expected reduction of NOX at sensor 2, it will set fluid quality trouble codes and ultimately go into reduced power until the fluid quality test has been run and passed. The ECM does NOT vary the dosage of DEF to compensate for poor fluid quality.

Freezing does not significantly reduce the effectiveness of DEF as commonly believed. It is so easily available there is no reason to stockpile it. I only carry an extra 2.5g jug of it, and that's probably not necessary. It is a few bucks a gallon at a truck stop.

nola69746702 · 06-04-2016, 09:31 PM

Thanks for all the info, when we started using DEF in the shop, I did do research, as I stated, but I can see there is much more info out there now, so maybe I can stop telling the operators about the freezing and etc, I never did understand why you wouldn't get it at the pump, At least we are getting a lot of knowledge on this subject. Great group!!!