Ford was think about getting the most MPG as possible.
You may see a slight decrease in your gas mileage.
Thats what Fiestas are for.
I think of Mustang as their Hot Rod Model. Fettering a Stang with 2.73s seems a bit bi-polar to me.
And as one who changed up from 3.31s to 3.73s, there was a 1.5 MPG hit on the highway on the 4.6L.
2008 manual GT with deluxe trim, Edelbrock e-force, FRPP GTB Mufflers. 3.73 gears, Coast Ultralight Drive-shaft. 18" OEM Polished Bullitts, Webelectric Sequentials, XM built into the Shaker 500. Alarm and Escort RedLine.