I get about 16 mpg with only city driving. I reset it with each fill up, and am pretty sure the reading is correct. I didn't buy a GT for good gas mileage. However, the GT does do better than the Porsche I had set up (12 mpg).
'06 GT, manual, Satin Silver, lt. grey cloth int., IUP.
MODIFICATIONS - Goodyear F1 GS-D3s; 245/45 on 18x9, 275/40 on 18x10| Progress Technology springs & sway bars| Steeda adj. panhard bar, panhard brace, front control arm brace & bushings| strut tower brace| Tokico D-Spec dampers| CHE adj. LCAs & BMR relocation brackets |drilled & slotted front rotors| C&L intake| BamaChips SCT tune| FRPP 4.10 ring & pinion| Pypes off road H-pipes| FRPP GTA mufflers.