Ford has issued a technical service bulletin for 2011 Mustangs, due to problems with the fuel pump and fuel gauge.These problems affect both the V-6 and GT models.
In a nutshell, the problem involves false readings from the fuel gauge, which in some cases may have the reading drop from half-full to a quarter-full to empty. Additionally the trip computer might display a zero miles to empty message. The problem might occur intermittently.
In addition, Ford says that affected cars may take only 7 to 10 gallons of fuel during refueling, despite the fact that the tank capacity is 15 gallons.
The cause appears to be a faulty fuel pump module that isn't drawing fuel from the fuel pickup. The solution involves replacing the electric fuel pump and the left-side fuel level sensor. The repair is covered under warranty and should take about an hour.