Did you wait for the car to depressurize the gas tank before opening the cap?At my first fill-up (5-10 miles after "Fuel Low" warning), I filled until the pump automatically shut-off the flow.
I didn't notice until later that the pump receipt showed only 5.658 gallons had been dispensed. And my fuel indicator is about two and a half segments from the full mark.
Any guesses on why the shut-off stopped so short of filling my tank?
If so, it could be something wrong with that gas pump, or your vapor recovery system.