Today I was mostly looking at the tank sender, vis a vie inaccuracies there of.
Tank depth 270mm
Sender projection into tank 220mm
It's never going to be any where near is it!
With 125mm of fuel in the tank my display says 0%
To sum up when the gauge hits zero you have half a tank left.
The sender works on a float principal, as the float rises and falls the resistance changes. Unfortunately it's not a lever arrangement that can be bent a bit, but a float that travels up and down 2 slender wires thereby changing the resistance.
3.5 ohms = 100% full
70.5 ohms = 0%
The only way I can see to make it more accurate would be to change the thickness of the wire so that when the float was at the bottom it read 0% thereby giving a 10 ltr. reserve.
To be honest I think life is too short for me to bother.
A dip stick might be a better option!