I'm going to guess the tank is actually full and it only takes less than another gallon to overflow. Or, is it like mine and able to take another3 gallons, more or less, after the pump shuts off.
My T-F tank reads like this:
When the 'Low Fuel' warning comes on, I have about 10 gallons left in the tank, but by that time I have driven about 500 miles. That is a stock Ford sending unit in the tank.
When I fill up, I drive about 100 miles before the gauge reaches the F mark and then it is about 100 miles/Quarter tank.
I usually get about 17-18mpg on the road, but also use 15mpg to calculate fuel remaining.
Did you have to drop the tank to change the sending unit?
Do you still have the old sending unit?
Could you bend the float arm (I'm assuming it still works that way) down to change the reading? Bending the arm down would mean the fuel level would have to drop more to produce the same reading. I'm guessing it would take about and inch change in position to get it close to my gauge readings - if they are about what you want.
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