When my coach consumes 50 gallons of gas, my generator no longer picks up the gasoline. How do I know it's 50 gallons. My generator shut down when pulling off the off-ramp to get gasoline on one trip. It took 50 gallons. The generator has consistently shut down when I have approx 350 miles on a tank. My gauge is not very accurate. It does not come off of the full mark until I travel anywhere from 100 to 140 miles. When the needle shows half a tank, it usually takes 50 gallons and like your motorhome, I have 75 gallons.
2003 Dolphin L/X 6320