How to test unknown fuel gauge.

67Dart273 said
Factory specs don't tell you much because the float/ arm may be bent some from "factory." They were not necessarily "that accurate" but "you hope" you can run it down to E and keep going awhile LOL

There's a device.......about 50 bucks.........called a "meter match" can calibrate the thing against some variation. Don't know how far they will compensate

TechnoVersions - MeterMatch for Analog Gauge Correction

I've written "a bunch" here (hop most of it is correct LOL) about the problems with these gauges and accuracy. It's not just the senders, sometimes it's also connections in the cluster, wiring, the accuracy of the instrument regulator, etc etc. Here are the factory resistances: