Bought a nicely modified 05 5.4l scab with 37's finding out exact gears it's eather 4.56 or 4.88.

getting 12 mpg consistently

everyone post what you are getting.

 

probably 14-15 average i guess..08 Screw..3.73's and 275-65-18 stockers also 5.4 and a Gryphon.

 

City 13-14 Highway 16-18 Volant CAI w/ ram air, edge, magnaflow. Stock Fx4 18" wheels/tires. 3:73

 

Right now, the mpg screen on the dash is reading 9.2.

 

Expect anywhere from 10-20mpg. There's already several posts about this...

https://www.f150forum.com/f4/mpg-help-39315/
https://www.f150forum.com/f4/fuel-mi...5-4l-fx4-2302/
https://www.f150forum.com/f4/5-4-gas-milage-15095/
https://www.f150forum.com/f4/better-gas-mileage-48539/

 

last tank I got 400 miles with stock tires

 

For this to be a "fair" and true MPG query, we should ask what mods and driving habits folks have with their trucks; these play heavily on MPG readings (as stated in many posts on this subject in the past).

My average MPG readings over the past year and a half are 18 city, and 22 highway, without towing. Since I don't tow a trailer often, I cannot provide a fair MPG reading, as true MPG should be averaged over a couple of fillups, driving at the same conditions (towing/not towing).

Here is what I've done to the truck (again, these mods have been on my 2005 4.2 V6 automatic transmission truck for over a year):

1) Free flowing muffler (single in/single out)
2) K&N semi cold air intake kit
3) Bosh platnum 2 plugs
4) Superchips "performance" tune (when I tow, I load the "tow" tune)

Because it's a 4.2, I don't get (or expect) the jaw dropping, knuckle scraping, chick drooling performance of the 5.4, so my driving habits are mild to say the least. The truck is my daily driver, a 10 mile a day to/from work, with two to three trips a year from Dallas texas to Orlando Florida round trips. The truck currently has 84K, and is in excellent tune with all maintenance being performed on a regular basis.

Hope this helps the stats.

 

IDLH What size tank do you have?

 

I have totally stock 2005 5.4L. I generally get about 16.5-17.5 MPG's with mixed driving (65% highway 35% city). I get as high as 20 on all highway runs. With the 37 gallon tank I can get over 700 miles per tank.

 

2006 supercrew 4x4 5.4L 265 tires stocks were 245, Edge Evolution, I am a spirited driver, run my truck down the highway about 65-70 on the two lane coming to town from my house. I don't feather the gas from stop lights. But i don't floor it either.

I get around 12.5 average with mine. My Edge tells me I am getting 14.8 but it lies.