A 6.2 gas engine pulling a 36' 5th wheel trailer will take lots of gas stops on a trip.
Your also traveling a interstate so truck stop type fueling will be quicker unless your tight and want to drive around off the interstate looking for a mom and pop fuel station big enough for your length...and your trailers height.
As one poster mentioned I also like to use google maps/street view for looking at places we want to stop....or which lane I need to be in to make a exit/entrance for the service I need.
Most trips for us are not planned so Its a must have for my co pilot to do google maps/street view while we travel and need to stop for the nite or fuel.