DEF in diesel SCR systems.

I don't know about shelf life, but my truck sat outside some this last winter. I plugged in the engine heater and it got down to -10 below zero (F). I had no problems with the DEF in the tank in the truck. The truck drove and handled, and the engine rumbled, just like it does in 80 degree weather. I'm pretty sure that electric heater built into the truck engine does not heat up the DEF.

Slownsy wrote:
Ok what about when it sits in a truck over a long period of time at high temps 80-90 or more.
Frank.

First of all, the storage temperature is based on the average daily temperature, not the high temperature. I'm attaching an article below that goes into a lot of detail on this. But here is a key example from the article:

"EXAMPLE: In 2009 the two hottest months in Phoenix Arizona were July and August. The average temperature for both months was 95oF (35oC), according to the data from the National Weather Service. The average daily temperatures for these months ranged from 104oF (40oC) to 85oF (29oC), while for
some days daily highs reached 115oF (46oC). For areas that see these average temperatures DEF shelf life would be 6 months."


Secondly, even though the DEF starts to degrade, it does not necessarily mean that it has to be drained and replaced in the vehicle. When the concentration goes below 32% Urea, the only adverse effect is higher usage. If the concentration goes below the calibration point for the system, you'll get a warning on your dash that indicates the DEF needs to be replaced. This is very unlikely, and would only happen if the vehicle was stored for an extended period of time in very high average temperatures.

DEF Shelf Life Article

Jim

We have a bulk tank of it on the farm for our tractors. It is kept in a shop that is heated in the winter. In the summer the shed is slightly air conditioned but, that is mostly to keep the moisture level down so things don't mold.

The last bulk tank was 2 years old before we got it empty and we had no problems with the DEF.

The biggest problem has been the bulk tank pump gets stuck and has to be freed up before it will run.

My brothers 2015 Ford 1 ton message center does tell him in the winter that it's "cleaning the exhaust filter" a lot of the time. But, he spends a lot of time idling it and using it on short trips. As soon as it warmed up this spring the problem went away. The dealer told him the No.1 fuel used in the winter makes it need to clean the exhaust filter more often.

Ok what about when it sits in a truck over a long period of time at high temps 80-90 or more.
Frank.

DEF shelf life has been discussed here numerous times. For the majority of us, we do not purchase in bulk and therefore do not keep it around long enough to worry about expiration dates. Pretty much much a buy and use as you need it. Of course those that buy it at a truck stop pump have no worries at all about expiration.

But a reminder is good for those who may be new owners of DEF trucks.

RAM pickups did not require DEF until 2013.

Walaby wrote:
I purchased a Ram 2500 diesel in Jan. It's a daily driver, plus TT hauler. So, far, I've driven it daily for two months, and 4 (or maybe 5) tanks of gas, and still have just over a half tank of DEF. I don't forsee the need to store def. I'll buy a 2.5 gal, and fill it up before my trip to Florida.

Mike

Mike - If you'll be pulling your rig when you head to Fla, plan on using more DEF than when you're driving around town. I know when I'm towing, I use quite a bit more than when I'm not. But it's really not a big issue because you can buy DEF most anywhere now.

Jim

I purchased a Ram 2500 diesel in Jan. It's a daily driver, plus TT hauler. So, far, I've driven it daily for two months, and 4 (or maybe 5) tanks of gas, and still have just over a half tank of DEF. I don't forsee the need to store def. I'll buy a 2.5 gal, and fill it up before my trip to Florida.

Mike

Do you have a question? If not, what is your point?

Many, many threads about the paranoia of DEF and virtually none of those threads have proven the paranoia is justified.

Yes, I own a modern diesel that uses DEF and it has NEVER been an issue.