A few years ago the tech at Autometer told me this - note what he says about aftermarket or repop senders:
"Also, just for future "FYI", the gauges are calibrated to match a factory sender, which is very non-linear. 10 ohms = Full, 25 ohms = 1/2, 50 ohms = Empty, and 73 ohms = below Empty. Which this said, most after market, or reproduction senders are built linear which means that E & F will be correct, but everything in between will be skewed."
With my aftermarket sender I experience the same thing.
