CAI and exhaust maybe got me 1-2 mpg gain...and I strongly stress maybe.

what they did do was to make me happier with the truck. I love the way the exhaust sounds...and the CAI growls and rumbles like an old 4 barrel.

the 2 combined actually sometimes influence me to goose the throttle to hear some noise

 

what kind of mileage are you getting?

 

You must do a lot of downhill driving..

sure, even with 35" tires, I'm running 4.56 gears which atleast brings it back pretty close to stock ratios.. I'm running X3, AF1, and Magnaflow true dual exhaust.. so like I said, stock or not, it more than likely won't happen.. look at Josiah.. he's running 37-38" tires last I checked.. you think he or any other lifted trucks are honestly getting near 20+mpg?

If it looks like bs.. smells like bs.. or ever sounds like bs.. its more than likely bs..

 

to OP: I live in Hawaii. the statewide speed limit is 35 mph...they claim to have a highway system that has a speed limit of 55 mph

that being said...I currently get 13 mpg...city only driving.

back in October before I moved out here and had access to better gas, I usually pulled 14-15 city mpg and about 18 mpg highway on the short jaunts...about 16 mpg mixed.
I have no idea if they get that kind of mileage or not. I doubt Josiah is flying b.s. though. No reason to. He has plenty of his own gafs that he has freely admitted too

and I still can't believe you are comparing your lifted truck against a stocker. there is a huge difference between them...your tires alone are making your truck about 200 lbs heavier than mine...and then the rotational mass of those tires is killing your MPG and HP...gears/tuner or not.

 

The disparity in mpg claims may just be a missunderstanding.
They may be truthfully stating the dash display.

My BMW reflects 41 mpg on the dash, cruising on the highway.
When I fill up and divide miles by gallons it equals 27.

 

BUWHAHAHA! Maybe going 45mph in a 70 all the way in the right with the hazards on.

I personally do not consider anything "highway" speed unless it's 65 or greater and I don't think anyone is getting 22mpg at those speeds with an F-150.

 

Which rims/tires are you running? Pics?

 

That's true. When you can't predict when the light will turn red on you and you have to stop, that is going to cost you.

 

Geez. You drive that slow on a highway in Florida and you'll get run off the road. Everybody is doing 75-90.

 

Ive gotten 20.6 with my 4.6 w/3.55's, I have 33's and an Autospring as well...got 20 all day long when it was stock

 

When I had stock tires I would be able to get 20.5 mpg highway. That was going around 67mph or so though. 2005 2wd supercrew.

 

This might help with the question as to whether mods do anything for mileage...

This is a follow-up to this post: http://www.ford-trucks.com/forums/61...e-results.html

All data points are reformulated unleaded, except for the last two which are E85.

Gas 4/9/07 to 7/6/07: 87 Octane with 10% ETOH purchased at the local Kroger and at the same pump every time.
Gas 7/12/07 and 7/16/07: E85 (85% ETOH and 15% Unleaded) purchased at the local Kroger, at the same pump.
Driving Habits: 60 to 70% city. I'm not heavy on the pedal on a regular basis but I occasionally like to hear what I've paid for.

Modifications
Tonneau Cover: UnderCover installed 6/2/2007
CAI: Volant installed 5/12/07
Cat-Back: Magnaflow Model 16614 installed 4/12/07

Results:
There is a modest increase in mileage that has little to no significance. The slight increase could also be attributed to the fact that the engine is still breaking in and as of today has only 6200 miles. There is no evidence of a substantial individual or cumulative affect of the three add-ons. Also, seasonal reformulation of the gas around here could also affect the results.

However, the most interesting finding is that the trip computer's MPG estimate looks accurate. I found this surprising seeing as I've read many posts that questioned it's accuracy. I reset the computer after every refill.

The Average Cost/Mile:
Unleaded: $.08/mile
E85: $.11/mile
There are only two E85 data points so I assumed the same miles (about 235) and extrapolated 12 more E85 points to provide an average of 264 miles per tank for all data points. Given average miles driven this represents about $8 per tank difference or roughly 27% difference to run E85.

Keep in mind that my only unleaded source is reformulated 10% ETOH gas for added oxygenation. If you are in area that receives non-oxygenated gas the differences will be greater.

 

My mechanically 100% stock '08 S'crew 2WD with 3.55LS rear end consistently gets right at 20MPG Highway if I keep it at or under 70 (measured by doing the math when I fill it up here; if I go by the computer it says 21+!). I've found that I have to change air filters religiously at 10K miles to keep up mileage though (Fram replacements are a whopping $10). I'm cheap enough to "make Abe Lincoln cry out when he gets pinched" so I'd rather do that than spend hundreds on a CAI.

If you go 3.73, you take up to a 1MPG hit and get more low end punch. The 3.55 rear end loses a little low end acceleration, but it's still plenty to tow the boat (have a 3500lb boat) and haul the mail in general. I do have a soft tonneau (for function, not MPG since myth busters proved that the weight of any cover actually hurts MPG more than aerodynamics help). I bet a lighter Supercab truck would do even better than my S'crew. And an FX2 "street" truck is also something to consider. So, you can do it, but not in the usual dream setup folks want of 4X4 with all the goodies (without some type of mechanical mods that usually impact something else expensive).

 

You might touch 20+ MPH under perfect conditions (no ac, tailwind, 60 MPH, etc) but you will normally get in the high teens on the highway and mid teens in normal driving. You will find that this is the best you will do with any full sized truck. Some diesels would do it in the past but with the new emissions and fuel requirements, it is now history. The new diesels seem to use about as much fuel as gas and it is more expensive. The largest truck I ever had that would get 22 mpg on the highway was a 1991 V6 4X2 Dakota.

 

If your dad's diesel got 22 on the hwy, likely the f150 will be close to that as well. Much of it is your style of driving and the terrain/payload/type of fuel. I can get 20 + on the hwy in xlt screw, 4x4 3.73 axle with the 5.4. My best is 23 with a 20 mph tail wind while hauling a mototcycle and other payload of about 1k pounds.

These results would be close whether you are buying any large 1/2 ton except the big gassers - like the 6.0 gm or the thirsty Hemi. The best mpg Ive heard of is the Tundra by 1-2 mpg but the initial cost is so much greater that you'll never break even..... Same concept with buying a diesel these days.....