2011 G37 Coupe with 32K miles.
Fuel Gage and readout on the NAV screen say almost empty. MPG readout between the Tach and Speedometer says 25mpg. Filled the car and it took 12 gallons for 300 miles which works out to 25mpg. So 1/2 the fuel measuring system is bad? I searched and saw Black Betty has had a gage problem in the past. I am going to try some Techron in the tank as that is supposed to help clean sending units.
Suggestions before it goes to the dealer for warranty work?

 

Techron wont do squat. Remove the fuel pump. Clean the contacts on the fuel sending unit with some electrical contact cleaner and a foam Q-tip. Takes less than 30 minutes.

 

Time for another dealer loaner to beat on. See previous posts about too old and fat to get under car, or remove the back seat. As long as it is under warranty, THEY can do it. Days are long past that I do my own wrenching. Last thing I seriously wrenched on was a Cafe Racer/A-Gas drag bike which was also my transportation in high school and college.