I have the Boyd tank with the 0-90 ohm sending unit and matching gauge from Summit. I have now run out of gas 3 times because I never know when the tank is empty. Yesh, I know, just gas up sooner. If I completely drain the tank the guage reads just above empty. Adding 4 gallons brings the guage to 1/4 full. If I fill it completely til I have gas in the neck, it reads just over 3/4 tank. Help! What is wrong with this damn thing? I would rather it had 2-3 gallons at the empty point for a cushion but I cannot seem to make it happen. Thanks..