you have a fuel light ? luxury.
My fuel gauge is typical of defenders I think, no movement for about the first 1/4 of a tank 

. By the time I get to half a tank I probably have only  a 1/3 tank left, the bottom half of the tank empties quickly. I don't worry too much, when it gets into the red, I change to the aux tank, (42 l) and start looking fora fuel station. My aux tank has the same characteristic, because it has a land rover level sender fitted. The change over lever operates two  x 2 way valves and a  micro switch that changes over the gauge sender as well.
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