Def fluid

Have used Super Tech DEF from walmart for the last three years 38K miles with no problems. I fill it up when I'm going to pull the 5er more than 3000 miles. Other than that I add a gallon at a time when it gets low keeping it as fresh as I can.

I agree that DEF is universal. But I have run into DEF which has long passed its expiration date. And the clerk had no idea that there is an expiration date.
so I would advise that it is ok to buy DEF from Walmart as long as the expiration date has not come and gone.

Its the universal answer from the dlr. I had a 2011 GMC and the tank had to be replaced at 600 mi and again at around 75k mi. As well as a sensor a couple of times. It has nothing to do with the def you are using.

Have been buying Walmart Peak Blue DEF since I bought the 2012 F350 new. Never a Problem. Same brand that is sold at local auto parts stores.

In 40 thousand miles I have only used Peak Blue DEF in 2.5 gal boxes. All but one from WM. When it get to 1/2 on the gauge I drop by a WM and put in a box, and let them recycle the box.

I always check the date code. Here is a sample of how it works.

This is from a Dec 6th 2016 post on another forum.

The code on the box is "12170412431 A"
Doesn't look any different other then the "A" at the end

12 = where made

17= year made plus one

041 = days remaining in the year that is was made

2431 = Actual Batch code

DEF made today by Peak would have

xx19284yyyy code.

That is, it was made 284 days before Jan 1st 2019.

Chris

Hogwash, DEF is 35% Urea solution. It's the same no matter where you get it.

BK