I am running 20 inch wheels. Tires are 275/65/20 3.73 limited slip, 5 speed torque auto.

 

I have the same Truck, I love the truck, but I hate the gas milage. I was getting better milage when I had my 04 2500 GM with a 6.0L gas engine.
I installed a Tonneau cover a couple weeks ago and I've notice a 2 mpg increase. I have a job 1 truck with about 15,000miles.

 

Hey, that is great info sharing out there. I will have to pump up those tire to 80psi. Also if kept at 65mph (17.5-18) big difference as compared to 70 (13-14). Also have used pure acetone in the fuel forr the last 2 fill ups, got at least 1 more MPG. I will try the motorcraft additive next and see if there is a difference.

 

yea Im praying it gets better
2008 F-350,v-10,6-speed,crew cab,long bed,fx-4
800 miles and 9.9 MPG mostly city no towing

 

"Third, and Volony? the Service Manager is telling me that the ECM is programmed and I should see an increase in mileage at 3, 6, and 10k miles as the motor breaks in - that it's a programmed cycle - are my eyes turning brown for a reason? "

My selling dealer did not tell me that but a Ford diesel guy at a dealership here in Florida did tell me that and I have got to say that I have noted difference. The biggest was at the 6K mark..big jump in MPG..@ 1.5mpg) we are now at 7500 miles and looking to see what happens at 10K..

 

I'm also around the 12-13 mpg around town (F350 CC SRW, 3.73 w/auto). What is killing me is all the hills I need to pull around home. I literally can't keep under 20 psi of boost no matter how I baby it. I swear if I lived in a flat location I could get 18-20 mpg easy...

 

cough bull**** cough 52k miles, still the same fuel economy as day one

 

Just towed a 13000 lb. 5th wheel 700 miles and varied my speed from 63 mph -75mph and couldn't get past 8.0 mpg. I have a 2008 crew cab 4x4 6.4 diesel automatic 3.73 gears that has a DPF delete Superchip and no DPF and converter. I would hate to see how bad it is without these modifications. Truck has 5000 miles. Sold a 2006 6.0 and got 12-13 mpg with the same load at 75 mph. Ford needs to do something about this or everybody is going to jump ship.

 

That's pretty bad. I have no mods and I get 9 mpg plus or minus a half depending on terrain. I tow a 48 foot 5th wheel enclosed trailer (empty 11k) loaded almost 20k. Over 52k miles of the same ol mpg.