So I had to make a 2.5 hour trip(interstate). My speed ranged from
67mph to 76mph. In the morning I didn't run the A/C, but in the afternoon,
of course I ran the A/C. I averaged 21mpg!!!! Now I have the 07scab
with 5.4 2wd. Sorry for the ramble. Just had to share. I almost have enough money saved up for the Gryphon!!!!! can't wait.

 

Must be nice......

I'm lucky to see 18 mpg when on a long stretch doing 60 mph.

My truck likes to chug when I get on a 4-lane hwy. Mileage drops off to 16 or less when I run 70.

I know a lot of guys do a lot worse than that, but I don't have any suspension or wheel or engine mods of any kind, basically bone stock FX4 with a tool box, and the 3" DWV intake.

 

After running three tanks of gas through my new daily driver Ranger with the 4.0 V6 I am averaging 20-22 mpg with mixed driving. I almost went with a 2009 F-150 XL instead, but was concerned that the fuel economy would make it a poor daily driver choice over the long term. If I can keep averaging that 20 - 22 mpg over the long term I'll be happy.

 

I wish most of my driving was on the high way. I manage to pull 17 MPG's on rural roads and city driving. Hopefully my new exhaust hasn't put a dent in that.

 

I wish I had that luck, my 4.0 got 17 on average, a few times 20-21 but down as low as 13 too for a 2wd I was surprised. The mileage in my 5.4 is not much different.

 

I have an 06 SuperCab XLT 5.4L 4x4 with 3.55ls rear end.

I've had the truck since March 2nd and put nearly 10k on it. My worse tank was 16mpg. I'm now avg around 17, and with a recent trip nearly unloaded and on the hwy at 70 for 350 miles I fetched a cool 19.7 mpg. I have a K&N drop in and single 3" exhaust. I'm very happy with the truck thus far! However I feel the bigger tires and level kit etc...Might take away some of this mileage!

 

21? Wow. I've never done better than 15.5 on the highway in my 04 FX4.

 

I must admit on two things. I did put in a K&N filter.
And did change the exhaust si/do thrush muffler. Mine also
has 3.55ls rear and no other mods. I bought the truck
almost new. It was 1 year old with 10k miles. Now it only
has 21k miles. I do drive normally drive rural roads and usually
avg 17-18 mpg.

 

Just an update! I have installed my new Gryphon on 8/27/09. Just by running the canned tune for the trans tune (level 1) I am getting 20-23 mpg on the highway!!!!! I was transferred to a new town with work to keep from being layed off and now I drive 60 miles one way. Most of it being highway. I have been running between 68-75 depending on traffic, with using the cruise 98% of the time. The highway I travel on is very hilly, and not many flat spots. Today I averaged 22.915 mpg and I was calculating using the miles vs gallons method, not the avg mpg on the Gryphon. I am very pleased with my purchase and can't wait till my custom tunes come in.

 

This is exciting me... I get great mileage too man... the gryphon is in my future as well.

 

NICE.

I made three trips from CT to FL, and honestly averaged 75mph (80-85 south of Richmond) and got ~19.7 each trip.

 

Congratulations on saving up enough for your Gryphon!

 

Just got a e mail today. My cutom tunes are in !!!! To bad it's gonna be a day or two to install them. Since I have to drive 60 miles to work now, and I work 10 hour shifts. I dont have much time after work before its bed time. up at 5:00 am and in bed by 9:00pm. Come friday they will be installed.

 

Def let us know.. you sound like you get similar mileage as me... These 5.4 2wd's do great on gas if you are easy on the pedal