well anyways, back to the subject. i had an 04 f150 heritage(03 style) it was reg cab long bed 2wd 5 speed 4.2L V6 and 3.08 rear end. with a K&N 77 series intake i got about 22.5 combined mpg. highway i would guess was about 25-27. city was about 17mpg. stock combined it got 18.9, with K&N drop in filter(cone shape) it got 19.9 combined. well i traded it in for my 08 and the intake was taken off the 04 and i put it on my 08. my 08 is a reg cab shortbed 2wd 3.55 rear end 5speed with the 4.2L it gets about 19 combined. it is about 450Lbs heavier than my 04, also is less aerodynamic and is higher off the ground. but both trucks with the intake i could play around all i want and still get 17+mpgs. this summer i took my 08 to the track, drove 85mph for about 45 minutes, ran twice at the track, drove home 45 minutes at 85mph and raced a few cars on the way home that were at the track. then filled up, i got 17.25mpg. my 04 had 235-65-16s i think. my sig shows my 08's

 

07 screw with 3.73, stock 255/70/17 tires, gott's intake with edge and all i still get is around 16mpg. and that's if i baby my truck.

 

06' screw 4x4 XLT 4.6 285/70/17 AVERAGE: 15.5 MPG

 

Actually this was on Mythbusters. A clean and dirty car had the exact same MPG. Then they put a layer of clay on a car and put dimples in it to make it look like a golf ball and it had a significantly higher MPG. (They added the weight of the clay to the clean and dirty cars so the weight was exactly the same.)

FYI, in my hilly town I get 15MPG average give or take. Tonneau, e-fans and tuner (canned) here.

 

Agreed. I'm running stock 20's/meats with the 5.4L

 

I'd put a AFE stage 2 CAI on it and an exhaust, I have that on mine and I get 18-19.3 mpg

 

5.4L XLT 6.5 bed, s-cab or is it s-crew? I have four doors, but not full doors, the front has to be open.

Was getting 16.9 on 230/70/17
I went to 245/70/17 and a new SI/DO knock off flowmaster.

I drive 23 miles to work one way, 21 or so of those are on the highway at 65-70 when I was getting 16.9.
so 46 miles a day, if i don't eat out and pack my lunch.

Now with the new tires and exhaust, I have been setting my cruse at 55 or 60 and so far I have gotten right at 190 Miles and I am just below half a tank, I think slowing down from 65 and maybe even the smaller muffler may put me at 18, as long as the tire size change didn't hurt me too much.

Really the stock muffler is like 2 foot long and almost 1 foot around, my new one is so tiny compared to it, and its tucked up under the truck, so that there is no way to damage it, even if I bottomed completely out fully loaded and something broke, the frame would hit the ground first.

I have not filled up yet, but I am guessing at least the same if not better, I used to get 300 miles out of a tank, so far I have managed almost 200 at just under half a tank.

Well ok, I have filled up, but that tank was spent crusing with the new tires and exhaust in town most of the time at less than 25 MPH and i still got 13.5 MPG.

Other wise the truck is bone stock, I have a AEM brute force intake on the way, and I plan on getting a tuner soon.

I was running 93 for a while, no change in MPG on stock tune, went back to 83, I have 87/89/93 here.

Unless I am a tool, Miles traveled / gallons of gas pumped.

Edit,

No clue on gears, how do I find out?
Help?

Had a few mistakes.
tire size and mpg before. and rating of pump gas, all changed.

 

270 miles / 18.1 gallons 14.9, kinda sad I was getting 16.9 but it looks like a few of the little things I have done to the truck has caused it to drop.

went from 230-70-17 to 245-70-17, removed the bug deflector and removed the old muffler and put a SI/DO on.

 

heck this guy i work with has an 08 5.3L silverado 4x4 and just from getting bigger tires and wheels and getting a leveling kit, basically just a front end raise i think 2 inches, he dropped almost 3mpg. is only getting about 14.5 now. was getting about 17-18

 

5.4L stock tires 255/70/17 no extra weight have a bug-deflector
Gear 3:73
Avg 12.5-12.8 MPG mostly city driving
Once I got 18.8 MPG with 4 ppl in the truck on freeway holding steady at 60 mph

 

hmm 4X4 I take it?

 

I have to agree w/ bambo here, but to also add truck size, GVW, size of the tank, weight of the truck w/ the tank full, 4x4 or not and so on and so on. I laugh sometimes when I read threads like this because people are comparing apple and oranges. There are so many variables when it comes to mpg's. When I bought my truck, I was lucky to get 10 to 11 miles a gallon highway (even though the window sticker said 14 city, 18 highway, what a bunch of b.s.) truck is an '05 s-cab longbed with a heavy duty payload package w/ a 163" wheelbase, 4x4, 5.4 engine, 8200 GVW, 4.10 rear and at the time 245/75/17's on it stock. I think the tank is 35 gallon tank. At the time it was the longest, heaviest F150 you could buy stock. Now, I wouldn't even think of comparing my mileage to any one else's on the site unless their truck were VERY similar to mine. Mileage questions are just way to broad to properly answer. I did alot to improve my fuel mileage including a cai, Xcal ll tuner, tonnea cover, and cat back duels and at this point I average 14 to 14.5 a gallon highway and usually w/ the cruise on at 55 to 60 mph. Last summer at one point I was getting 16 highway and had done nothing to the truck for that to occur, so not sure why it increased like that, but it didn't last for very long. Went back down to 14.5 not long after that. I could probably eek out a few more miles a gallon if I hadn't put on a weather guard box full of tools and bigger tires, though I did change the stock steel wheels for polished aluminum, big difference in weight. Most people I see posting 16 to 18 mpg's have lighter, shorter trucks. And as eharri stated, driving habits have a lot to do with mpg's as well. I am very heavy footed when going from a stop (it's just so much fun with the tuner) so I could get better mileage there also. Usually with these kinds of threads, there's not enough information given to truly give any kind of comparison.

 

^x2

 

Wow that is a long truck!

I consistently get 18ish on the highway (06 5.4L screw 5.5box 4x4). A lot of it has to do with keeping the truck below 2000 rpm cruising. And in the city, keep jackrabbit starts at a minimum.

Another thing to consider is properly inflated tires. They will rob mpg if they are under the proper pressure.

 

Proven on the Tv show Mythbusters that tonneau covers DO NOT make it better.. It slightly adds drag, the beds are designed to create an air bubble where the air then flys over top of this bubble..

Plus I had a fiberglass one.. Added weight to the bed, added drag. Took it off, have never thought about putting it back on.