You don't say if Gas or Diesel, hopefully Diesel with a heavy rig like that. Low price for fuel is nice, but not at the expense of getting stuck, so we generally fuel up at the major truck stops and use the truck lanes. The RV lanes at Flying J's are a joke if you have a big rig, not to mention those that sit there and have lunch. We use the GoodSam Pilot/Flying J card and get the cash price plus an additional 8 cent/gal off on Diesel. Pull up to the pump, swipe my card, enter my PIN, pump my fuel then leave, don't have to go inside unless I want a hard copy receipt. Works for us with a 40' plus 5er.