[hatzie]

I plotted the resistance (Y) vs coolant temp (X) of the GM sender in excel based on some published sender data. The data starts at 20 degrees and ends at 250 degrees. This gives a more visual representation of the non linear sender behavior.
The fuel sender is an interesting weighted curve as well. The first @11/16 of the tank sweeps across 1/2 tank on the gauge. At 1/2 tank shown you only really have just over a 1/4 tank left. At E you still have 1-1.5 gallons reserve. According to one of my GM service news in the mid 70's (somewhere between 73 & 75) GM weighted the fuel gauge this way to give the impression of better fuel mileage. My F250 plow trucks' fuel gauge is weighted the same way.