If it works as good as it claims, this would sure beat pulling the sender out to make adjustments. For $60 it seems like a great deal. I might pull the trigger and buy one. I’ve managed to get my low end readings fairly accurate, but my fuel gauge still won’t read further than 3/4 full even with fuel spilling out the filler tube. My only question about it is will it play nicely with Bob’s ELFI?
Almost every Ford constant voltage regulators have a design feature that allows you to also set the gauges correctly. Usually on the back side is a small trim pot with a post that can be turned. Often it is potted in epoxy that can be broken off. Simply turn the post until your gauge reads correct. I do this with a quarter tank of gas, figuring this is the most important set-point.
This is a cool idea for hot rods where the gauge and sender don’t match at all.
I have a vested interest here so keep that in mind.
Start with the gauge tester $30. It will test fuel, temperature, and oil pressure gauges and verify that you have power from the instrument voltage regulator. If your gauge reads correctly (70 to 75% of the time) then the problem is your sender. Fuel senders can be rebuilt and calibrated and then they will be more accurate than new when used with a proven gauge. Fuel senders almost always read low after many years.