Shelf life of DEF fluid

[wagonmaster2]

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?

[N-Trouble]

A month at 122* is really a lot longer than a month. Temps fall every evening so your only going to be at those temps a fraction of the day.

[ktmrfs]

Norskeman wrote:
Temp(deg F), life expectancy
32, Infinite
50, 75 Years
68, 11 Years
86, 23 Months
95, 10 Months
104, 4 Months
122, 1 Month
140, 1 Week.

I'm suspicious of the life at higher temps (95+). it wouldn't be hard to end up where the temp is 122 or higher much of the time if your in a desert climate especially driving during the heat of the day, and then park in an asphalt drive exposed to the sun.

And with GM they purge the def line whenever the engine shut down. you can hear the pump going on shutdown. probably to keep heat exposure down, and they also state that is to prevent any freeze damage in the lines. IIRC there is a heater to thaw out the DEF if it does freeze.

[mkirsch]

The DEF tanks in vehicles are designed so they won't split if the DEF freezes, and are heated to thaw the DEF should you want to run your diesel in extreme cold temperatures.

[wagonmaster2]

NinerBikes wrote:
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?

Excellent comment in your first paragraph, at what temperature will it freeze solid, if at all? Never thought about that end.

Sorry about the duplication, must have stuttered with my finger.

[wagonmaster2]

NinerBikes wrote:
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?

Excellent comment in your first paragraph, at what temperature will it freeze solid, if at all? Never thought about that end.

[Bumpyroad]

11 years at room temperature. no problem storing some up. what do they define as "life"? 80% effective, 50%, etc.

bumpy

[Norskeman]

Temp(deg F), life expectancy
32, Infinite
50, 75 Years
68, 11 Years
86, 23 Months
95, 10 Months
104, 4 Months
122, 1 Month
140, 1 Week.

[N-Trouble]

3-5mo in Cold weather is not a problem. DEF degrades much more quickly in warmer temps

[NinerBikes]

A good rule of thumb is don't buy it until immediately before you need it, once your DEF gauge on vehicle shows that you are low.

[MEXICOWANDERER]

As an aside...

UREA is the prime ingredient in Chevron's TECHRON and Shell Oil's NITROGEN gasoline additive.

[Winged_One]

I have stored my truck for the last 2 winters (about 5 to 6 months each). No issues with DEF.

[2oldman]

DEF shelf life thread 9/28

[NinerBikes]

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?