8" lift on 38x15.5x20 mud grapplers WITH Speedo within 1 mph hwy empty and 3:73s I averaged 14-15. Mixed driving 12-14. I'd have to guess there is something going on with your truck or your Speedo is off

 

I get about 14.5-15mpg overall. It varies a little depending on what I'm doing but by the time I fill up again it comes out to about 15mpg.

 

 

Same with the hutch mod. Have the parts in the shop just need to get some dry weather and run the tank down kind of low. Welcome to guzzle's In-tank Hutch Mod Web Page

 

Hutch/Harpoon, one of my favorite modifications to date. Everything else you do to or for your truck doesn't make a hill of beans difference if it does not have fuel.

 

Truck with bed cap, HWY mpg's are just below 21 mpg (US gal) at 63 mph in near ideal conditions (gentle throttle, flat road, little wind, warm ambient temps etc.) City mpg = ~14 mpg.

Truck with 3,500 lbs. truck camper loaded in bed and pulling an 3,500 lbs. enclosed cargo trailer, HWY mpg's (US gal) are around 15 mpg at 63 mph in near ideal conditions (gentle throttle, flat roads, no wind, warm ambient temps etc.) City mpg = ~11 mpg.

 

+1. If the OP's odometer isn't working, would that make his truck one of those "unlimited mileage" thingies?

 

I can confirm low to mid 20's mileage as well with all of the above mentioned factors combined with no traffic lights, and perhaps a slight tail wind. There is a guy (Big Dave) on Ecomodding forum, (100+ Hypermiling / ecodriving tips & tactics for better mpg - EcoModder.com) with a 7.3 that regularly reports mid 20's and slightly above. He has configured an aggressive air dam under the front end, as well as an aerodynamic bed shell. Think he is also a 2WD guy w/a 6spd manual and a 3.08 rear diff. Suspect much of his driving is at highway speeds as well.

 

...what mileage can I hope for with something like this? <;~o

It's a 2003 7.3 V8 Powerstroke diesel.

 

I'm sorry, but I don't buy this 26mpg stuff!!

MY L99 F-350 Crew Cab XLT Long Bed Dually 2wd automatic, 4.10 gears, and Leer model 122 hi rise topper HAS gotten 17 on flat ground here in Florida with cruise set on 60 which is a hair less than 2k rpm.....

I generally get about 15mpg average on straight DINO Diesel, and about 14mpg on commercial made B99.9 Bio-Diesel....

BTW; I run Power Service Diesel Kleen gray bottle during the summer for the added lubricity unless I'm using my favorite fuel in the whole world the beef-fat based B99.9 that I get from Glover Oil here in Melbourne Florida.

MY 7.3 runs very well and very smooth as a rule but much more so with the Bio, which, BTW is usually .05 to as much as .30 LESS than Dino Diesel, just depends when I catch it.

 

I have a early 99 as well and I see the same mpg so yeah I 100% believe him. I can drive for almost a week off of 20 dollars. That's back and forth to work 4 days a week and then some other places as well. My work is 30 minutes away btw.

 

I didn’t believe it till I got some recent mods (and fixed some serious exhaust/boost leaks) and went from Low to mid teens to the first two couple hundred mile trips getting 23.6 and 25. I have an auxiliary fuel tank that I can get very accurate refills in as well. I was completely and utterly shocked. I also pulled my horse trailer this weekend and got 17.5... on the same trip I normally get 10 to 11 max..