It's just urea and water.
Just don't buy outdated DEF. It's like milk, but the date it expires is in 'code' sometimes on some bottles in stores. Wait till you're really low to add more.......that keeps most of it that you are using at the same date.
To be honest, I don't know 100% if that is accurate.......but I've been told this by 3 mechanics.
Walmart has 2 different brands........one is about 2.5X the price of the other. Either one works.
Only thing I hate about the Chevy is the DEF deal. Fillup is under hood, which is stupid. And the DIC panel only says "OK" until it gets to 30%, then it tells you percentages. Don't run out! Most new trucks will slow down or stop if you do.
There aren't any hills in N. Florida!