I have 2019 CC Standard Bed GMC Sierra 5.3 4WD. Either my tank isn't getting full, my gauge isn't working or my tank is not the 24 gallons spec'd for my truck. When on empty (fuel light on and miles to empty showing low), it only took 20.5 gallons of gas. I filled it till the pump shut off, but the gauge is showing slightly below full. This has happened at 4 different gas stations (2 Costcos, 1 Shell and 1 Fast Trip).
Has anyone else had this issue? I am still under warranty, but I was hoping to have an Idea of the issue before I went back to the dealer.