Cow urine is cow urine.....
I used to have a cattle farm and have had lots of Crap and pee and after birth on me and none of those could eat a whole through concrete Luke that nasty def junk.
DEF is DEF. 32.5% urea, and 67.5% DI water. No additive packages or custom formulas. Other than one top off at a Flying J, my truck has only seen Supertech DEF. If NAPA or O'Reilly has a deal on theirs, that's fine too. I always check date codes, and make sure the seals on the bottles are intact. I plan to get a tester just to do spot checks.
DEF Refractometer
www.tooltopia.com
As far as all def is the same, I would have to politely disagree. We're all entitled to our opinions, but I look at it like, not all oil, gas, fuel, food, clothes quality is the same. Sure there genetic make ups are all pretty much the same, every manufacture has there own recipe ( per say), so they can set there products to compare to other manufacturers and say this is why were better. I don't think I'd be going to far out on a limb to also say, probably most people have there favorite ( whatever, you name it), most folks get certain products because they believe for what ever reason that product is of better quality than other like products.
In saying all that, I'm the guy who will only use rotella t oil and shell fuel. I'll only drink great value soda and eat Oscar meyer dogs . For 40+ years I've only worn dickey work pants. So as you can tell, I'm a firm believer in the old adage of all things are not created equal. Whatever that equal bottom line is, is up to each individual to decide. MOPAR DEF ONLY IN MY TRUCK, , unless I can't find a dealer that sells the 2.5 gal jug. Thats why I always start looking for one once i get to half a tank full, then put it in once i get down to a quarter