Gas level indicator & actual milage not matching

Hello, this sounds like a likely issue with the fuel sending unit - located with the fuel pump in the fuel tank. It could be a sending unit concern itself, or a concern with wiring to the unit. Has there been anything serviced or repaired in that area in the recent past? It's not common for this kind of thing to suddenly fail without any other circumstance. Usually there's a correlating event that can give clues as to what has happened. Can you think of anything? Seek local guidance at a shop near you for testing to figure out the cause. Use this link to find some shops near you that can help with your concern: www.repairpal.com/repair-shops