Well, to keep it short, there are several things here. The first is that there are several ways to measure 'octane' so your numbers, and ours, may vary.

Gas is rated higher by how slow it burns during it's explosion in your cylinder. Not how fast.
When gas is mixed with air and then compressed, and ignited, it burns very, very fast.
So if you can make it 'explode' a little slower, you can use the explosion to push the piston a little better.
You can start the explosion nearer the top of the pistons travel, then the slower explosion pushes the piston down sooner and harder.
If the octane of the gas is too low, the explosion happens too quickly and hammers the top of the piston. This is ping, then detonation.
So to enable the use of lower octane gas you delay the explosion till later in the pistons travel, allowing the piston go down more, further from the blast, and giving it more volume to explode in. It makes less power, but doesn’t ping or detonate This is done by retarding or delaying the timing. So the spark happens when the piston is pretty far from the top of its stroke.

So to get to octane vs. power, higher octane explodes slower, and thus makes less heat in a given engine.
And is no advantage to an engine with low compression and late timing.
No gain, maybe some loss in power.
By setting the compression higher, and/or advancing the timing, that is making it go off sooner, you can get more force/horsepower from the motor.

Factory F-150 trucks for America, are all set with low compression and late timing. The timing is controlled by the PCM computer. A tuner (among other things) can move the timing more advanced, and thus explode the gas earlier, when the piston is near the top of its travel, thus enabling you to get more power from the gas, due to the longer explosion.
But that would require higher octane gas.
Hope this is somewhat helpful
Chris

 

Takotruckin, My truck seems to be very similar to yours. I drive fairly conservatively and do not have a lead foot by any means. I'm getting around 12 in town and 14 on the highway. I realize I only have 5000 miles on the truck, but there really has not beem much improvement as of yet. Mine is also very gutless. One day an Escape absolutely smoked me from a stop. Sure wish I would have kept my F350. I'm very disappointed in this truck.

I had an 01 F150 Screw 5.4 and that truck felt much stronger and got better mileage. Not sure what the story is with this one.

MJS

 

My speedo and Odo are about 5-7% off since I switched to 18" Lariat wheels with all terrains. That being said, I get about 225 miles on the top half of the tank (with a 5% mileage correction) with my 2WD 5.4 SCREW. I cannot bear to go any lower on the gas gauge than that, or it may never be full again!
I'm sure I drive like someone's grandma...

 

dont get me wrong, i love my truck, but i cant stand this mileage or power(lack of it). the service manager happened to come into my work today, he told me that he gets 15 around town. and to take it in whenever i want. hopefully i am gonna take it in tomorrow so they can check it out. is yours an 04 or 05? i have an 04 with a fairly early build date, it sat on the lot for about 10 months! got a good deal though.. i hope they can get this figured out though.. i just figured these trucks got horrible mileage, but then i started reading these posts and realized something was wrong with mine. i also noticed something was wrong when my friends stock SCREW with 33x13 tires could spin them without power braking.

 

I called my local dealer today and mentioned poor mileage (not true) and erratic rpm fluctuation (true). They suggested just reporting the low mileage and offered to re-flash my module as a known fix. Service rep even mentioned he thought that Ford should send out a recall TSB to have them all done, as gas was over $2 and felt they owed it to their customers. Also intend to ask about the 6qt vs 7qt problem I have seen so much about....even though my paperwork said 6 qts, my dipstick is a hair below top mark.

 

Back in the eighties my Dad used to nurse 40 mpg out of his Subaru all the time.

Of course he pissed off every driver within 30 miles doing it but the funny thing is the few times I rode with him in it, we always reached the light and pack of cars that passed us at the same time they did.

Ahh, the old man. God rest his soul.

 

Yeah, miss my dad too.

On mileage, anyone that wants can pick up a Suzuki Swift/Metro and get 40+ at the freeway speed limit. That's with the stick, their automatic reeks for mileage, 30-36 is best we ever got out of any of 6 we had. Best 5 speed 4 door was a 95, which is still in the family.
It was one of my fleet cars, got 55-58 all the time. Gave it to my nephew who was driving long miles when it had 64k. He 'retired' it at 189k. He drove like a kid, and got 46-50. Plus never had anything go wrong with it. Just oil changes, and two sets of plugs in it's life. Heck, it still runs fine, and has the original clutch.

We had an 86 Sprint, Chevy by Suzuki with the three. 55-57 all the time, and 62 on the freeway at 65 mph.

Suzuki builds the best small gas savers on the market. Always has.
My little Tracker(Vitara) gets 25, which is lame, but auto a/c 4x4, power windows, etc. may explain it...
For those that really care about saving money, buy a Metro, and enjoy.
Me, I'm gonna keep driving my F-150.
Chris

 

Suzuki????Subaru???? wut do thoes have I4s or V6?? these trucks have V8s(most of us) they are ment to eat you gas...thats why ford felt bad so they gave us 37 gallon gas tanks to make thier mpg look better...personally i dont care for mpg. i would have boughten one of thoes 60mpg crappy ugly hybrid cars if i wanted more mpg. and im definitly not driving like a grandma all day tryin to get that one more mpg. not worth it. i let my puppy loose

 

thanks chris adams

its the first time i was told this its good to know more now. but please tell me then if this is the right conclusion. for our f 150 trucks it would not make much of a difference it switch from 93 octane to 95 or higher.

also because of the increasing prices of gas, there is also an increasing number of feul savers in the market, but there is one here that is suppose to be very good its called the Khaos super turbo charger, i have a few friends who use it and confirm its effectiveness, one has a ford explorer truck and the other a suburban. would it be possible for you to check out the web www.fuelforce.net and go to faq and tell me what you think. it is suppose to improve fuel and air mixture, if thats the case would the computer just compensate what ever increase or decrease in air, which means it wont do anything.

thanks so much for your help

 

50% fuel savings? HAHAHAHAHAHAHA.

This sounds like another Tornado air scam. Save your money. They don't work and you'll find that the testing labs are on the payroll and not objective in their results.

 

Increasing the octane above the required will do nothing good, and actually cost you a small amount of power.

I googled the Khaos Super Turbo Charger and it is another one of the standard scams that happen every time gas gets more expensive
. During our first two 'energy crisis' here in the States there were about a thousand different versions of this thing. At best they do nothing, usually they decrease your mileage.

People who add things like this are usually very happy, and try to convince everyone that it works great. Three reasons.1. Placebo effect, tell them it will get better, and they will assume it is better. 2. "I spent the money, it must be better, or I am an idiot". That is the biggest one. 3. They drive much more carefully, unconsciously tilting the test in favor of the new device.

As you say, the computer will 'compensate' to any changes induced from the device. The modern overhead cam motor does a fantastic job of mixing and blending the gas. The three valve 5.4 gets more horsepower per cube than a racing motor from a few years ago.


As a side note, this thing is supposed to induce turbulence in the air intake. That is the reverse of what you want on a fuel injected motor. On a carbureted motor you mixed the fuel at the top of the carburetor. On injection, it's at the bottom, or in the cylinder itself. On injection, you want the air coming straight and fast, not tumbled up.


I wish things like this would work, but if they did, I'm afraid many big companies would snap the technology up and be putting it in the car from the factory.

A good example is the Honda SC heads. They had them exclusively, they worked, so every other maker came up with their own variant.
Another good idea is the variable cam timing concept. First used on racing cars, now on a 5.4 truck.

Believe me, the makers will put every cost effective mod on the truck from the factory.

Now you can add horses by adding intake systems, at least on the 5.4, but that is mostly because of two things; 1. The return doesn't equal the cost. At 200-300 dollars cost, a 5-8% increase would not be worth it to most buyers, just the enthusiasts like you find here.
2. The 5.4 3 valve engine is so new that Ford has not quite perfected the intake. On a 4.6, which uses an intake developed over years, there is little real increase in performance from adding an intake.

Improving the exhaust 'might' lead to better mileage. This is because Ford has to make the truck to a certain noise level to please a million customers in many places. So they are quieter than strictly required for mileage. Open the exhaust too much and you get worse mileage until you are running at high speed.

A tuner or programmer mostly gets around US emissions laws. They are not normally intended to get better mileage, just more performance. They do that, but again only around 5-12%. Something for the enthusiasts again. And that is performance, not gas mileage.

Tonneau covers or any smooth cover over the bed will improve the gas mileage, but mostly on the highway. Around town you won't gain much.

If you are driving in the islands, well, I don't recall a lot of highway, but I admit I mostly saw it from Manila harbor, and through a drunken haze...many years ago.
Still, don't think you have a lot of steady freeway driving, if I am wrong, adding a tonneau, the less expensive/lighter the better the return.

In the old days you could yank a lot of emissions devices off an American vehicle and get a lot better performance. Nowadays the stuff is a lot better integrated, and more efficient.

Not saying you couldn’t find a couple miles to the gallon there, but it might not work out as well as you might like. And modified trucks, with warning lights popping on your dash does not help the resale…
Sorry I can’t be of more help.
Chris

 

thanks that helps.

you are right chris not a lot of freeway here we only have about 50 km going south of manila and another 100 kms going north. i do a lot of out of town driving thou. but because of a lack of freeways our mailage is not very good because we have to go thru a lot of small towns who use tricycles for public transportation and the buses stop and go all the time as they pick up passengers along the way. manila is another story it can sometimes be one big parking lot. its a blessing to have a nice comfortable truck.

despite the traffic conditions there are lot of very nice places to visit, a lot of nice beaches, golf courses, mountain resorts and in last 2 YEARS our nautical highway has been done so now we can go from one end of the philippines ot the other by driving and crossing islands on a ferry. we hope to do this next summer with the family. with 7100 islands there will be plenty to see and visit.

thanks for all the info.

 

Wow, sounds nice. If I ever get back in that part of the world, I hope I get a chance to see some more of those 7100 islands. That sounds like a drive to remember.
I was last there as a kid, and was more interested in getting drunk,etc. than enjoying your fine country.
Well, have a great day, and take care.
Chris

 

I just got a job that makes me travel up to 300 to 400 miles a week in my own car and the way every things been going i had to do something about mpg so this is what i did went to the local ford dealer and traded my old f150 in on this little ranger







i went from 13 hwy to 39 hwy mpg its got a 17 gallon tank and i did 393 miles the first tank if you do the math thats like awesome and it cost me $40 not $120 to fill up