It might cost a bit more, but I get my DEF in the 2 1/2 gallon jugs from WallMart. I absolutely do not trust the truck stops. I'd rather pay a little more and KNOW what I'm really getting than take chances a pump at a truck stop is contaminated. I stopped getting diesel from truck stops too and use regular car fuel stations. The last several truck stop type service stations I've stopped at have just been absolutely nasty, dirty, and unappealing. The truck lanes are just yuck. I'm talking Flying J and Love's ... just plain dirty. If the lots, pumps, and access areas to the pumps are a mess, it only stands to reason they don't tend to anything under ground either. Just like going into a restaurant and seeing a cock-roach run across the floor. If you see the one cock roach in the lobby, who knows what's going on in the kitchen you can't see.