The gauge in mine takes a while to show the amount of gas. Usually about 10 mins before the needle moves. My sisters 05 Explorer gas gauge only goes up a certain amount when filled and is supposed to be replaced by the dealer. There’s defiantly a problem with some of these gauges.
I had an odd occurrance last night driving back home. I filled up completely(fourth fill up so far). And when I got back on the freeway I noticed my gas gauge was still low near the red. I checked the info screen and it said I had 60 miles to empty. I starting getting pissed thinking the gas station had just screwed me out of $30. But slowly, and I mean slowly, the gas guage started going back up and the DTE increased as well. Maybe I was driving so fast that all the gas was pushed to the rear of the tank or something