I bought the car about 2 weeks ago and when i went to put gas in it, the gauge read Empty...i throw 20 bucks into it, and about 6 gallons later it wont let me add gas, as if the tank were full...

So, could my gauge be off by half a tank or is there just something making it think theres a full tank in the car or am i just a complete moron?

Full tank= Half tank on gauge.
Empty on gauge = half tank.

 

Mine is very sensitive to how the pump nozzle is put into the tank fill opening. If I put the nozzle way in, it shuts off too soon. I have to pull the nozzle out an inch or two from full in then run the pump flow less wide open to get a good fill.

 

Also the gas guage fluxuates a whole lot. Some hills I could have a 1/4 tank.. drive a mile down the road and ill have 2/3s. Check your gas gauge at a flat spot

 

my guage didn't read right when the sender had a loose ground wire.
I also notice some gas pumps are different and seem to shut off way too early before the tank is full. I don't like those.