Hey putting up a post for the Chi town folk.
Bolingbrook I55 truck stop, I was in the area, stopped in to top off DEF, they have it on the pump (cheaper and convenient) I asked if any of the diesel pumps have a small nozzle? Pump 10 has a small nozzle. Filled up with "truck diesel" ; supposed to be better (higher cetane) and fresher.
They're kinda old school there, to use the DEF pump or fuel pump, have to give them your card and drivers license, they swipe it when done. There's a donut looking fitting you need for the DEF pump and the jeep, they have it at the desk.