Checking to see what real world mpg is on v6's. If you own one please post. I'm on the fence about one and the 31 mpg's is very appealing to me as I driver 90 miles a day to/from work.
User reports arent up yet but the governments own site is very helpful at breaking down the costs and carbon footprint and so on of the fuel requirements of a car.
Imo your question op has too many variables. For instance my pos villager pulled down 31 mph on a 35 mi cruise at 55 mph. You bump speed to 70 and mpg goes to crap 22 mpg. City 17/18 mpg. There always seems to have a speed point where mpg goes to crap, stay under that and all ok, you start passing cars on a 2 lane road then it really goes to crap. My 03 will pull down 25 mpg the 94 tbird 4.6 27 mph at 55/60 mph. but at 80 it goes to crap. Even the 94 tbird 4.6 a old nascar shaped car. I'm sure the new stang isn't quite as aerodynamic. The 03 is a brick at high speed in comparison to the tbird.