Chevrolet GMC 2002 Owner's Manual Supplement page 17

Listed are four situations you may experience with your
fuel gage:
D
At the gas station, the fuel pump shuts off before the
gage reads full.
D
It takes a little more or less fuel to fill up than the
fuel gage indicated. For example, the gage may have
indicated the tank was half full, but it actually took a
little more or less than half the tank's capacity to fill
the tank.
2-14
D
The gage moves a little when you turn a corner or
speed up.
D
The gage doesn't go back to empty when you turn
off the ignition.
None of these indicate a problem with the fuel gage.
For information on how to fill your fuel tank,
--
see "Fuel Filling Your Tank" in the Index.
For your fuel tank capacity, see "Fuel
in the owner's manual.
--
Tank Capacity"