it totally depends on how you drive. my car is rated at 26 city, 37 highway. i get 35 city because i coast all the time. i know its illegal but whatever. downhill-coast; red light- coast; car brakes in front of you-coast; speeding- coast down to limit (if you feel like it
) basically, if im not on the gas, im coasting. my car is pretty much only in gear when i need it to be. anyways, my car isnt a z06 obviously, but im sure i would get much better than the posted mileage even for the z06. of course, id be much more inclined to wind a z06 out...