EXAAAACTLY,,,only I can go you one better than that,,,,,mine has the Tow Boss pkg. which comes with 4:30 gears, and your right, It does one hell of a job towing 12,000 lbs at 10 to 11 mpg real well. What I found that helped is that I went to 19.5 commercial 14 ply tires on Brentz direct fit wheels.(265/70r19.5) that are 34.5 tall, effectively cuts the gear ratio down to app.3:93. which helps, with the factory tires mileage sucked at highway speeds due to the 31 inch height.

What rear end gears? What size wheels and tires? 4x4?

And the biggest question... was that 22.24mpg divided by hand or by the trip computer on the truck?

I am getting 16mpg f250 crew cab, 3:73 gear, 4wd, stock tires and its a 2002, anyone have a truck like this that they put the tuner in and what did your mileage go to? I am planing to also put 4" exhaust and an intake on it, would love to get 20mpg or better. I talked to Jody at DP Tuner yesterday told him I was going to do a 5" exhaust, he said that that was to big would lose power. Has anyone found this to be true or heard anything about this?

He's right, the 5" exhaust with a 4" downpipe loses torque, we just took one off of my future son-in-laws Excursion and went back to a 4" system with a 3 1/2" downpipe, and it helped the way the truck ran. The 5" is more for the guys running the big injectors and propane. The 5" we removed was a Silverline, and the 4" we put back on was a Banks, the silverline had to massaged to fit around the rear shock, the Banks system fit perfectly,,,,,,,,and he did remove his converter and used the offroad pipe with both systems.
The 4" system, and we used an Airaid airbox system on my 7.3 when I had it with 34.5 tall tires with the 3:73 gears, the truck never even knew the trailer towing the bikes was back there. I never really did a hiway trip without a trailer to say what mileage was. The taller tires helped as much as anything. (10 to 12% taller than stock height)

Also installed a RollnLock bed cover to cut down air drag at the tailgate, not sure if it helped, but common sense told me that at 75 to 80 mph the tailgate had to be causing some drag.

What is the size that tires start hurting mpg? I am thinking that I want to put 35's on with a 4" lift. Is that going to hurt mpg? Anyone have the 4" lift and 35's, what are you getting?

I would be more concerned with power and braking loss.

I had no power loss issue with the 35s and a tuner.

Braking power is not diminished much.

With my truck, tuner and 315/75/16 inch BFG a/ts I just got 13.5 mpg the last tank. Used to be 14.4-5ish, but lost that with ultra low sulfer diesel. Thats a mix of highway and around town. Highway only is higher.

As soon as you change the injector pulse width with a chip or tuner the trip #'s go out the window. Any of the chips are a better solution in my opinion than the Superchips tuner. DP Tuner has a real nice product with a lot of support from the 7.3 Crowd.

Dave

On my 04 F250 4x4 I started out with the 315/75r16's (8 1/2" wheels) and got great mileage,,when I went to 325/65r16's (10" wheels) I lost some mileage. Both sets of tires were Toyo A/Ts.

What was your mileage before and after on those 2 different size tires? What was great?