Chrysler Repair: fuel gauge, fuel gauge, fuel sender

Question
After filling my fuel tank, the gauge stayed on full for about 120 miles or so.  Now it is slowly moving down.  I thought something was funny when I filled it up and it took more gas than the gauge showed.

any ideas?

Answer
The fuel gauge can become inaccurate when the sender in the tank changes its dynamics and your choice is to live with it and make a note of its tendency to mis-represent, or in most models drop the tank and change the fuel sender unit which is the part that goes inaccurate in most cases. Let me know the year/make/model and I can tell you how hard it is to change the sender.
Roland