Y are yall getting such low numbers? I'm averaging 15-17 in the city. I just put a half tank of gas in the truck and within 1/4 tank i've drove 135 miles. I only hae a programmer and cai. I have ran marvel mystery oil in the gas for the past 2 tanks and i just put a new fuel filter on it.

 

Hey all, haven't been around in awhile but came across this on google and thought I'd post. I have the same truck as Dixiemudder and right now I'm getting anywhere from 16 to 17 mpgs highway also, and our trucks are probably a little heavier than yours, roughly 8200 lbs compared to what, 7700 lbs.? When I first bought the truck, it was only getting around 9 to 11 mpgs. highway. Put a CAI on, custom tuner, exhaust and a few other things, switched to 93 octane, and got 14 to 16 miles there after, that's no joke. I've tried switching back to 87, but I lose almost 3 mpgs when I do, either with a custom program or returning it to stock, so I end up spending a little more money by having to hit the gas station more often than if I were running 93, and I don't care what anybody says, the truck runs better on premium. It has a 189,600 on it now and it started to lose some mileage in the last year and a 1/2, I was getting only around 13 mpgs, so I just replaced the cops, plugs (3rd time), injectors, fuel filter (3rd time), trans filter (3rd time), and just had the true duels put on 2 days ago and I'm back up to 16 sometimes 18 mpgs (depending on how often I step on it , then it all goes to crap!), and that's riding on 33's, truck came stock with 245/70/17's. Mileage results have alot of variables going into it, so not all are going to be the same, just some food for thought.

 

Your truck doesn't necessarily weigh more...its GVWR is just higher, thus you can carry more payload. Your truck, unloaded, still probably tips the scales around 6k lbs like the rest of us.
Do you have 6-lug or 7-lug wheels?

 

It's a 7 lugger. Yeah, your right about the weight and I do usually carry heavy payloads, it is my work truck.

 

The 04, 05, and very early 06's had some injector problems. It was serious enough that Ford issued a TSB on them and also extended warranty coverage on the injectors on the effected trucks. You might want to check into that. A leaking injector or two would negatively effect fuel comsumption.