I have been told that there is a small hole in the side of the guage and a small screwdriver can alter the guage. I was also told that you should first empty the tank and put in a small amount of fuel for the vehicle to run and then adjust the the guage to read empty. This will give you a good idea when to fill the tank when empty. I have not done this modification yet but will make it a winter project. I hope this helps.
David
