When my fuel tank say empty, and i put in 10 litres (2.5 gallons) of fuel, it still says empty. is this a faulty sensor or is it a reserve in the tank?

no, no real "reserve".


2.5 gallons is'nt too much. I know when I put that little ammount in, my gauge does'nt do anything. It does'nt even register on the screen.

same here when i have it toped off after only using 3 gallons it wont register untill i start the car a few times

My 94,and 97 mark dont register the fuel until i restart the car, or drive for a while, it take a few minutes to register it is normal.

mine goes on for restart after restart. i guess it's just the peculiarities of a 10 year old sensor.

The gauge usually is set to read where the pump pulls the gas from. Not the bottom of the tank so depending on tank design and angle the car is on. You may under some conditions get some extra range beyond the e or 0 miles indication. However under others you may be screwed and not get that say 15 or 20 miles you got once or before. Also the fuel is what cools the fuel pump and consistantly running low can cause the pump to run hotter and or pull air at times when its too low.