JK 23112

When I had my 2008 Mustang GT (4.6L, five-speed manual), it got 27 mpg on the highway at a steady 75 mph. I drove it to Michigan and back and then to Florida and back {with three people in the car!}. At 85 mph, my engine was only turning about 2200 RPMs or something like that.

The 3.73:1 axle would be more fun, but airplane gears are great for long trips. Even with a 3.15:1 ratio, the GT is still no slouch from zero to sixty.

shouldhavegottheGT

Sweet. May bump up to the 5.0 in the future if I can get that kind of mileage.

Mob Bomber

It was by hand calculation from how many miles we did divided by how many gallons we put in at each fill up. The on-board was saying almost 30 mpg avg. And to everyone how said I was babying it or driving wrong, I don't see how you can drive wrong on wide open highway cruising at 70 mph. I know how to drive my mustang and I'm pretty heavy footed almost every where I drive. In the city I mostly average 18-19 mpg. Oh, and the car is still bone stock. Just recently returned from overseas so I haven't had any time to modify the car.

Falcon Fixer

550 mile trip, 70 mph= 27.6 mpg
Intake, Dyno tune,Full Stainless Works exhaust.
422 hp, 390 tq.
I average 22-24

duckbubbles

The best on my 5.0 so far has been 26 highway granny driving. Maybe it's the auto that holds it back. I was expecting 27-28. I've also noticed that the computer is very accurate on this car. The puzzling thing to me is that I get in the 22 range around town, so I would expect more highway mileage than I am getting.

When my '08 was basically stock (Bullitt intake and tune) I got a best of 29.7 on a tank during a road trip. The whole trip (1800 mi.) averaged 28.5. After the blower went on, my highway mileage dropped to 24-25.

Frank

Dcobra31

19 mpg is the best I've ever done in my 5.0. But it can't be helped because there's so much stop and go in my area. I try to coast in neutral, and turn on the cruise control whenever I can.

Of course, as far as acceleration is concerned, I like to do that part myself

White05GT

Used to average 28.5 mpg hwy on mine with real gas. With the ethanol laced gas it's dropped to 26.5 mpg.

slickman

Driving like a normal person, Around town I get about 16 -18 and on the highway I get 24 - 27. That's with 3.55's and FI..

yellowneck86

I drove from the SF bay area to Sacramento and back and averaged 19.9 mpg in my 08...definantly not driving it like I stole it.