[donhov]

OK, not to argue but Ram dealer told me most DEF has a shelf life of 1 year. It possibly has sat on the shelf for 2 or 3 or even more months prior to your purchasing it. I was carrying a 2.5 gal jug in the rear of my Ram and couldn't tell you for how long. I no longer carry a spare. When I get around 1/4 or so on the gauge I purchase a jug and dump it in the tank immediately. No issue that way. Got this info when my problem message came on and dumped the jug that was in the rear of the truck into a 1/4 tank of DEF. After a few miles the message went away/cleared itself but prior to that I was in panic mode and called my dealer in Florida while I was in Michigan. Followed his directions poured in DEF and went on and finished trip with no further issues. Guess I was lucky but I no longer keep a jug in the truck unless I'm getting low.