I trust my gauge all the way down to the bottom of the tank. When I install a gauge, I set the float wire to read ) when the float is on the bottom of the tank. Once the gauge reads ), I know I am close to walking. By yanking the steering wheel one way or the other and watching the gauge as whet fuel is left surges from one side to the other, I get a "fine tuned" reading. When I can't get any movement in the gauge, I have only a couple of miles left at most.
Why are you not confident with it?