Are you asking for performance or mpg?
A tuner, exhaust, intake, etc will definitely give you more performance.
The best way to increase mpg is to drive like an old man.

 

Generally speaking, you can't get increased mileage AND more power thru the use of an aftermarket ECU (call it a 'programmer' or 'tuner' or whatever). You can tune for one or the other.
Now, are there some latent ponies waiting to be unleashed in the average vehicle?
Yes, up to a point.
A high flow exhaust and intake system will add a small percentage increase with nothing else done, the stock engine management system can adjust for this....to a certain extent.

Beyond that, to take advantage of bigger power gains, one has to add more fuel, either thru increased injector duty cycles and/or larger injectors. And of course, there goes your fuel mileage.
And once you enter into the world of forced induction well....that is a whole 'nother story.

Keep in mind the OEMs spend BILLIONS getting that balance of power and mileage. Do you REALLY think some company with a fraction of the resources can offer much?

 

^ tuning for HP is the same as tuning for mpg, you usually don't see an increase because you use all the new HP, which kills mpg. Fwiw, I get better (1.3mpg) running level 2 on my edge vs level 0 (stock). That's with gotts and a glasspack.

 

I added an aFe intake to my '05 5.4 and my mileage went from 12.5-13mpg to 14.5-15mpg.

hand calculated.

The butt dyno said it felt more aggressive. and sounded better with my MBRP catback.

As for my '09.
I will be adding a k&n and superchips tuner to it. with a k&n cai tune.

I also agree with freeing up hp and getting more mpg. As long as your not always using it with your foot.

with my '05 I had couple hills on my route to work when driving on the highway. prior to the intake, the truck would have to downshift to climb them. after I added the intake the truck/engine would growl a bit more but wouldn't need to downshift. the growl was a deep tone from the intake/low end torque kicking in.

 

My experience (limited as it has been) in the import world using HALTECH or POWER FC or Peter Farrell Supercar 'Pink' ECUs is that one CAN actually create a 'fuel miser' "map" that lowers the power output of the engine, and thus reduces fuel consumption, by reducing injector duty cycles, altering timing, and changing boost patterns on forced induction engines.
Not that many people actually DO this...it just is an option for these systems that have multiple selectable "maps" to choose from.

Without any experience in the world of F-150 aftermarket engine management systems, I defer to your knowledge here.

 

I'm going off of hot rodding, where the more efficient you can tune an engine, the more power you make for the same amount of fuel, which also increases mpg. I really don't think our 6000lb trucks would get better fuel mileage with 100hp vs 300hp, and if you could drive it easy with 500hp, you would probably get even better mileage.
There are several guys with superchargers (~400hp) that get 20mpg on the highway, for example.

 

Word.

I agree, the less hard an engine has to 'work', the better the mileage. I've had big-block trucks/SUVs that got better mileage than their small-block cousins simply because the larger engine just loafed.

 

It's actually that less fuel makes more power, to the point that every molecule of fuel is burned up in the combustion. In a standard factory tuned engine, a fair amount of the fuel is not consumed in the combustion to reduce the possibility of detonation, and reduce exhaust gas temperatures.

Simply adding less fuel to the point where less fuel is 'wasted' in the combustion process will give you more HP. There's probably 5-10% hp able to be gained simply from adjusting fuel trims.

Some vehicles when cruising even go to the other side of stoich and run something like 15:1-17:1 -- not sure what the F150 does, but lots of gains can be had there if it's still conservative.

Otherwise, typically way too much fuel is used under accel. It adds up. Things like direct injection allow an engine tuner to be more aggressive because they are guarantee'd a more even distribution of fuel and more precise timing..

 

So is this what programers do to increase HP and MPG at the same time?

 

You would have to contact a tuner to find out exactly what they change, but the fuel maps are part of it. So is timing and changing when the transmission shifts and converter locks up. For general readers, the 06 and earlier 5.4s were tuned lean from the factory and engine damage can be caused by an aftermarket intake. Use the search button for more info. This can be fixed with a tuner but isn't an issue with the newer trucks.