Gas gauge ????

[ffron69]

Last summer the gas gauge took forever to come off the F mark & then would fall fast. Between 1/2 & 1/4 tank the low fuel light would come on, and usually by 110 or so miles I was stoping for gas just in case it was actually correct and it'd take about 3.1 gal.

Over the winter I lifted (not all the way off) the tank to run some wires & now the gas gauge seems to work a little more normal. At about 145 miles I was at 1/4 tank with no light on & it took about 3.6 gal.

Can somene tell me what might have happpened and with no mods to the pipes or fuel/air intake what is normal mileage for a tank of gas?

Thanks