samhain7ExplorerNov 19, 2020Ram 2500 DEF fluidHi all I am on tank of gas # 6 on my new to me truck and thrnDEF fluid gage has barely even moved How long do you get on a tank of DEF fluid and how big is the reservoir? ThanksShow More
patperry2766Explorer IINov 21, 2020I'm getting between 7500-8000 miles on a DEF tank on my '18 Ram. Less when towing.Find a good truckstop that sells bulk DEF so you won't have to pay for the overpriced box stuff sold at stores. I'm paying about $2.50 a gallon there.