Def

hammer55-JAY

Senior Member
Joined
Jun 15, 2019
Messages
259
Location
Livingston,
have a kind of dumb question, for those that stay in a park for a while,, what about the quality of the DEF, does anyone worry about it going bad during a long time in one spot, especially during the summer months??
 
A year is usually it's limit.

TWO years.. From PEAK:

When stored under optimal conditions — between 12°F and 86°F — DEF has a shelf life of up to two years. If stored in warmer temperatures, shelf life decreases.

So I wouldn't be concerned unless you don't move for over a year.
 
Last edited:
Buy yourself a refractometer so that you can occasionally check your DEF quality. Simply draw a small sample and test it. This is the one that I have.



https://www.amazon.com/Refractomete...9Y2xpY2tSZWRpcmVjdCZkb05vdExvZ0NsaWNrPXRydWU=

I have the same refractometer. Easy to use. I also check the DEF I purchase off the shelf before putting in the tank. Throughout the year and when I know I am going to have some weeks or months of downtime I try to use up the DEF in tank before putting in more DEF.
 
I had filled my DEF tanks in February 2020 in preparation for a big trip....well we all know how that year went. We had some use that year locally but not enough to use much. I would pull a sample every month and check it with a refractometer and it always tested good. I also have the Bluefire monitor and can watch the quality on it and it was showing it down to 32% from 32.5%, still within acceptable specs. We just finished up a trip in 112° travel weather pulling a 11k trailer and finally burned through that tank just last week and never had an issue. Towards the end of that tank, with the added outside temps, the quality got down to 31.75% as heat does affect the quality but we are talking pretty high DEF temps, as you can see the DEF got up to 118°.
 

Attachments

  • IMG_7647.jpg
    IMG_7647.jpg
    110.2 KB · Views: 16
We just returned from WY and SD for the 4th heading back to NM. Temps were also 95+ and saw DEF temps up around 112F, worked great.
 
we put 12,000 miles on last year,, not going to stop, thanks,,

I had filled my DEF tanks in February 2020 in preparation for a big trip....well we all know how that year went. We had some use that year locally but not enough to use much. I would pull a sample every month and check it with a refractometer and it always tested good. I also have the Bluefire monitor and can watch the quality on it and it was showing it down to 32% from 32.5%, still within acceptable specs. We just finished up a trip in 112° travel weather pulling a 11k trailer and finally burned through that tank just last week and never had an issue. Towards the end of that tank, with the added outside temps, the quality got down to 31.75% as heat does affect the quality but we are talking pretty high DEF temps, as you can see the DEF got up to 118°.
 
Where do you get 2-3 drops of the DEF to test it? Just curious, I fill mine at each oil change but it never gets old on my F350 because it rarely sits for more than a few days.
 
We always buy our DEF at the high volume truck stops. I try to top the DEF before allowing the unit to sit for awhile. And after sitting for awhile, I try to run it low before refilling. The theory is to burn the old out and refill with fresh, after 88,000 miles this has seemed to be a workable plan. Have heard the horror stories of the DEF problems, but fortunately avoided this one.
 

Try RV LIFE Pro Free for 7 Days

  • New Ad-Free experience on this RV LIFE Community.
  • Plan the best RV Safe travel with RV LIFE Trip Wizard.
  • Navigate with our RV Safe GPS mobile app.
  • and much more...
Try RV LIFE Pro Today
Back
Top Bottom