Boss's truck 2005 has a 8" lift and 35"s and giant sized mudflaps. He gets consistantly 18-20 highway and 15-17 city. He drives like his foot is in a cast. I bet he never goes over 3psi boost. Also his truck has FICM issues and a lot of stiction. It will not start unless its been plugged in.
My early build 2004 no lift and 33"s will get 15-17 highway and 13-15 city. I keep it under 8 psi boost and clean out the turbo here and there. My truck fires up no problem down to -18 degrees with out being plugged in and has nearly all new injectors and a 5 month old FICM. I think driving style has ALOT to do with MPG.

 

Thank you for making my points.

1. The only way to accurately calculate MPG on a diesel is to fill it to the brim. That's the very top of the fuel filler neck. It can easily take 10 minutes or more while you wait the fuel foam to dissipate repeatedly.

2. If you properly calibrated your Scangauge, the MPG it reported would have been very close to reality. You need to calibrate your Scangauge. Start by filling the tank to the top of the filler neck. Then, follow the directions on pages 18-19 of your manual starting at MORE>FILLUP. (Don't worry about setting tank size. It's not relevant for MPG and GPH, only range.)

When you refill, fill to the filler neck again and follow the sequence starting on page 19 "5)" to properly calibrate your Scanguage. It is very accurate if you calibrate it correctly.

2a. IMPORTANT: Make sure you follow the MORE>SETUP>ENGINE instructions on pages 15 and 16 of your Scanguage manual. Do this before calibrating your fillup.

2b. After two calibration cycles, my Scangauge showed 25.9 gallons on an actual to the filler neck fillup of 25.84 gallons. Since the Scangauge reports fillup gallons to the nearest tenth, that's pretty accurate.

3. Set up your gauges to show instant MPG (MPG) and what I call "Tank Average) (Tav). That's the same number as the fillup GALLONS. Check out manual page 28 "Displaying a Trip Value as an XGAUGE:

TXD 14

RXF 800000000000

PRESS OK UNTIL YOU GET TO THE NAME SCREEN

(I used Tav for Tank Average)

Bring up MPG and Tav on your display, Seeing the instant MPG and how it affects your tank average will really show how "nice" your driving your truck. You'll also learn that flat stretch of highway is actually an upgrade and watching your tank average drop a tenth or two waiting in the McDonalds drive through is depressing. Pretty soon, you'll figure out things like the best MPG cruise speed for your truck and tricks like accelerating while going down hill to build up a little extra speed that you can carry into the following up hill at a lighter throttle.

I'll bet you can significantly improve your MPG by calibrating your Scangauge correctly and displaying instant MPG (a regular gauge) and programming 'fuel used' as Tank Average as I described above.

4. Nobody gets 22 or even 20 MPG on a level highway at 70 MPH on a 2004+ F250 4X4 without a 25MPH tailwind.

 

The only way to really do this would be to install a different fuel tank, put in 2 or 3 gallons and drive until it dies. Then take a reading. My hand calculated mileage varies by over 12 MPG(from my best to worst) depending on trip and driving habits and fuel!

 

How is that different than filling the factory tank to the top of the filler neck every time when hand calculating MPG????

Somehow, you've managed to think that I ever suggested a calibrated a Scangauge was an accurate substitute for determining MPG.

THE ONLY WAY TO ACCURATELY DETERMINE MPG IS HAND CALCULATION BASED ON TO THE TOP OF THE FILLER NECK REFILLS. IF YOU HAD A SEPARATE 3 GALLON TANK, YOU'D STILL HAVE TO FILL IT ACCURATELY, JUST LIKE A BIG TANK.

Using a Scangauge to display instant and rank average MPG can help you become a more economical driver. I went through the calibration procedure because the previous poster wrote his Scangauge reported MPG was way off.

 

Thanks for the info here, I didn't know I could do that. Just wanted to point out though that for 'Tank Average', TXD is 04 not 14.

Mike

 

I have gotten more than 22 mpg @70 with my 04 f250 cc 4x4, I have also gotten less, the worst that I have ever gotten was 13 with my old lifted 04 cc on 315s @75+ into a 20+mph headwind, mud tread 285s on my unlifted cc cost me as much as 4mpg on a loup that I made twice weekly from west omaha to bellevue and back, summer diesel and warm weather helped tremendously when I lived in PHX, 20mpg from PHX to Omaha is easier than from omaha to PHx. EVen my v-10 Xcursion will get 15 @ 70 if it is not windy, 12 if it is.

 

You're right, it's 0, not 1. Displaying MPG and "Tank Average" simultaneously can be a real learning experience in feather-footed driving.