Several people have asked me to document my gas mileage after the supercharger was installed. The reality of the matter is if you can keep your foot out of the pedal then you would see no change in gas mileage. However I don’t know anyone who would spend $5K on this much more power and not use it. 😉
That being said here are my results, the long and short of it is I put my foot in it everyday. I did not hammer it all the time, but at least once per day I made a spirited highway traffic merge or an entrance ramp romp. So the results are that I saw 20.4 MPG for city driving. That is within Fords specs for city MPG.
Below is a full highway trip. I went 110.3 miles using 4.573 gallons. That is a 24.1 MPG. Note that I was going 79MPH with 3.73 rear end gears.