:cheers:Just got 20.5 mpg highway on 93 octane driving roundtrip to CJ Pony Parts in Harrisburg to have my MagnaFlow Street 19100 Catback installed (that's my Triple Yellow GT in their sound clip video). Manually calculated, gallons consumed divided by actual miles driven, about 150 total miles.
Of course, I wound out the gears a lot longer on the way home just to enjoy the sound.
For anyone who is is using the car's computer to check their mileage, don't forget Ford calibrated it high to make you think you're getting better mileage than you are. Obviously it should be checked manually to get the correct mpg.
Hand-calculated 15mpg on each fill-up so far, just running around suburbia with a few short highway jaunts across town. Just shy of 1000mi, so not reading too much into this, although it's pretty much what I expected.
Latest Fresno-Boise Road Trip in February netted 28 mpg hand-calced, with a best tank of 29.5. At 8,500 miles, the car has definitely broken in some. Computer reads 1.5 mpg higher than hand-calc'd reality. GT AT Fastback, 3.15 gears.
@4100 miles... ive been able to get anywhere from 19 to 21mpg mixed hwy and city... not bad at all.... have not had long enough trip to really see better than 22 yet