i went probably 40 miles and used 1/2 tank. i need to do the test again though.

 

ya. test and don't go by needle. write down exactly how much fuel you used under what driving conditions and what distance
that will give us an indication on how far it is from 'normal'

 

Kalli is right, those fuel guages are not linear or accurate.
It seems like the first half of the guage is about 3/4 of the tank,
then the last half goes very quick, especially if you step on the gas alot.

For an accurate mpg, you have to fill it, then drive it 100 miles.
Then fill it again and divide 100 by how many gallons you filled it with.