Anyone looked under their 5.0 Cummins equipped trucks and can tell me the possibility of fitting a larger tank? I haven't bought a truck yet but this is one of my top choices minus the small tank. I drive 25k miles a year and on my old Tundra with the 26 gallon tank I disliked having to fill up everytime I drove it. The Titan XD according to fuelly looks to provide the same fuel average as the Tundra with the same tank size as my old Tundra, so I'd be filling up quite often. I know no one makes a larger replacement tank yet but I was just curious if the possibility is there?