Yeah for the first 5-6 thousand miles the mpg on my GT was 15-16 mpg 80% city 20% highway, after that I've been getting 17-18 mpg in the same conditions.
I will say that the newer models computer for calculating mpg is more accurate, in my 2011 V6 the mpg would be off by 1-3 mpg compared to manually calculations. The 14 GT is pretty spot on.
2011 V6 Mustang - Premium 202A Spec (Pony Package) - SOLD!
2014 V8 Mustang - Premium 400A Spec
6 Speed Manual, 3.31 Rear
Black, Charcoal Black
Comfort Package, Security System