better MPG on a 4.0 SOHC

So, I can't be the only one wanting higher MPG's from this engine. My truck specs. -

2007
reg. cab
long bed
electric shift 4x4 - Is there anything that could be disengaged, that isn't?
A/C
manual transmission
sprayed in bed liner
4:10 gears, with trak-lok in the rear - would getting rid of the trak-lok or swapping the 4:10 gears to 3:73 be worth it?

aluminum tool box and snowbear plow (both usually kept off the truck)

31" BFG tires - this right here might help, might hurt MPG's. Bigger tires than stock (stocks were about 28 or 29 inches) but rougher tread.

K&N drop in air filter (and I cut the bottom air box opening bigger)

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How about an e-fan?
reprogram the computer?
Flowmaster or Magnaflow exhaust?
Synthetic fluids?

Anything else?

What kind of fuel economy are you getting now, and how are you calculating it?

The mods you mentioned like e-fans, exhaust, and PCM calibration can all make improvements, but they usually cost hundreds of dollars so it takes a very long time for mods like that to pay for themselves in fuel savings.

Without know what kind of mileage you are getting it is hard to say what will and won't help.

The 4x4 isn't helping just because it's heavy. The transfer case is the only thing setup to disengage. The front is a live axle and so is always engaged, but at a cost of a measly .2 MPG. It will take the rest of your life to recoup the money in fuel savings you spend on converting it to an unlockable axle and the subsequent cost of repairs to whatever sucky system you put in (all the others were absolutely awful for reliability).

AC is not helping either. Unplug the compressor.

Manual trans is good. But your driving style here can help or hinder. The 4.0 makes peak economy between 2500 and 3000 RPM.

Spray in bed liner is irrelevant to the question at hand. I'm not even sure why you mentioned it.

4.10 gears are bad if you are on the highway, but good in town. I like 3.73 as a nice compromise for combined driving, but with your tire size 4.10 might be a good ratio. Again this depends on your driving style.

My bed tool box weighs like 5 lbs. I doubt that would have any real effect on fuel economy. The plow will suck the gas down, and the mounts are heavy as well.

K&N doesn't do what it says for MPG. It generally will hurt it because it lets in more air, as did cutting open your air cleaner box which was designed in combination with the intake and computer system. More air means more fuel. You have a lot more air now.

The factory fan doesn't suck up much power, but is a constant drag on the engine. You may see some fuel savings switching to an e-fan.

I'm not sure what you would hope to accomplish by reprogramming. A Ford issued program will never effect fuel economy. An aftermarket tune is usually done for power, which means lower fuel economy. You can get one custom done to bump MPG, but you will lose power.

Aftermarket exhaust will get you a nice sound. It will not get you better MPG, nothing noticeable anyway. If you do it wrong you can end up hurting economy though. This is another system that was designed and tuned in conjunction with the intake.

Synthetic fluids, well switching to synthetic oil after so many miles usually just gets you burning oil. Synthetic fluid for that trans is very hard to find, and synthetic gear oil is really really expensive, probably more so than any fuel savings will account for.



The end result of all this is a thesis I have put forward on many occasions to have it simply ignored, or worse yet ridiculed:

Trucks are for work, small cars are for good gas mileage. If you want to work drive a truck. If you want fuel economy drive a car. If you drive a truck because you want to look cool but don't like the fuel economy you need to decide which is more important to you.

Yes I agree, E-fan will help.
reprogramming computer for stock engine, IMO, isn't worth it, you can check with Ford dealer to see if there is a software upgrade available for your year, and if so the cost for doing it, new software will often have better fuel economy strategies.

Stock exhaust is already "tuned" for best performance in mid RPM range, you can change exhaust to move the power band lower in RPM or higher in RPM, it doesn't add power just changes when the lowest pressure is at the exhaust valves(tuned).
Depending on your driving habits this might increase MPG.

Going from 29" tires to 31" changes the axle ratio of 4.10 to 3.83, but the weight and width(friction) of larger tires is often a break even.

What can help you as the driver is a dash board vacuum gauge, the higher the vacuum in the intake the better the fuel economy.
The biggest factor in fuel economy is the driver's input.

4.0l SOHC engine has a Knock sensor, this was added because to increase the horse power to above 200HP Ford needed to increase compression.
When you increase compression you will get knocking/pinging on regular gas(87 octane).
You won't hear the knocking/pinging, sensor picks it up before it is audible, when sensor detects it the computer retards the spark timing to prevent it, this reduces overall power and MPG.
You can get an inexpensive OBDII bluetooth reader that you can use with a smartphone to display realtime computer data, and you can monitor many things like fuel trims and spark timing.
So in the case of the 4.0l SOHC going to 89 octane may improve fuel economy, IF(big if) the knock sensor is detecting knocks with 87 octane.

Octane is a heat rating not related to fuel economy, a gallon of 87 octane and a gallon of 91 octane will give the same MPG on an engine with 9.0:1 compression, 2007 4.0l SOHC has 9.7:1, around 9.5:1 you can start to get knocking/pinging with 87 octane depending on engine condition.
Ethanol raise octane but has less "power" per gallon, so 10% ethanol mix can prevent the knocking but will lower MPG slightly, but only slightly, the knocking and subsequent spark being retarded would lower it more.

"Winter gas" contains ethanol to prevent gas line freezing and in the winter the air is colder so that is a double whammy on MPG, colder air is denser so requires more fuel to be added, this makes engines "peppier" in the winter but fuel economy suffers.

adsm08 said:

Spray in bed liner is irrelevant to the question at hand. I'm not even sure why you mentioned it.

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Well, obviously I can't take it out, to take a little weight off.

adsm08 said:

4.10 gears are bad if you are on the highway, but good in town. I like 3.73 as a nice compromise for combined driving, but with your tire size 4.10 might be a good ratio. Again this depends on your driving style.

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Tires are getting old, new tires will be smoother tread and possibly back down to stock size. Can I wear out my trak-lok somehow or do I have to remove it to get rid of it?

adsm08 said:

My bed tool box weighs like 5 lbs. I doubt that would have any real effect on fuel economy. The plow will suck the gas down, and the mounts are heavy as well.

Well, it's aluminum, but I think it weighs more than 5 lbs. and being in the bed, does it effect wind flow around the truck when driving?

adsm08 said:

Trucks are for work, small cars are for good gas mileage. If you want to work drive a truck. If you want fuel economy drive a car. If you drive a truck because you want to look cool but don't like the fuel economy you need to decide which is more important to you.

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How about a 2.3l manual 2wd Ranger, with an e-fan?

Anyways, thanks for the help!

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My MPG's vary, from about 12-16, worse in the winter, worse with the plow on. Better with more highway driving.

Mike Tonon said:

My MPG's vary, from about 12-16, worse in the winter, worse with the plow on. Better with more highway driving.

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Fuel economy naturally drops during the winter, especially in colder climates. Lower intake air temps, longer warm up periods, denser air charge, and terrible winter fuels will cause noticeable drops in fuel economy for pretty much anybody. Snow will add rolling resistance too.

The plow hurts fuel economy in 2 ways. It adds significant weight, which negatively affects economy in stop and go city driving, and it kills aerodynamics during higher speed driving where weight is less of a factor.

If you're just using the trip odometer to calculate your fuel mileage, it could include an easy to overlook, but significant error. Make sure the odometer has been calibrated for your larger diameter tires. If it hasn't, then you're actually travelling further per tank than the odometer shows, which will falsely decrease your fuel economy calculations. (It may show you traveling 240 miles per tank when you've actually driven 280)

Yea, it was calibrated for larger tires.

Mike Tonon said:

My MPG's vary, from about 12-16, worse in the winter, worse with the plow on. Better with more highway driving.

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16mpg would be fairly normal, 18mpg on long highway trips, 12mpg is very low even in the winter.
You can certainly "drive it" to get 12mpg, wouldn't be too hard at all, which is why a vacuum gauge can help, real time "money out of pocket" gauge can be very eye opening, lol.

I would have a look at a couple of spark plugs, make sure they have that light brown color of good air/fuel mix.
If they are darker then it may be running a bit rich, exhaust manifold leak can cause that, dirty MAF usually causes lean mix.

Changed the spark plugs about 15,000 miles ago and they were all light brown and actually kinda clean looking.

Mike Tonon said:

Well, obviously I can't take it out, to take a little weight off.

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But it weighs next to nothing. If you want to save the equivalent weight stop wearing shoes and only carry your credit/debit car and driver's license, leave the rest of your wallet at home.

Tires are getting old, new tires will be smoother tread and possibly back down to stock size. Can I wear out my trak-lok somehow or do I have to remove it to get rid of it?

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Track loc does cost a bit in MPG, but again not much. It can be removed and swapped for an open carrier. The other option is to wait for the clutches to wear out.

Well, it's aluminum, but I think it weighs more than 5 lbs. and being in the bed, does it effect wind flow around the truck when driving?

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Ok yes, it probably weighs more than 5 lbs. However the only thing that keeps me from easily handing my own box on my own is the awkwardness of the size and shape. Nothing that light will, by itself, have a noticeable effect on fuel economy. The average number used is 100 lbs costs you 10% on fuel economy.

How about a 2.3l manual 2wd Ranger, with an e-fan?

Anyways, thanks for the help!

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Again, as I said, if you want to work have a truck. If you want fuel economy have a car. I find the entire notion of anything that comes factory equipped with a cargo bed and a whimpy little 4-cyl engine to be absolutely ridiculous. I can see more use for tits on a bull or a screen door on a submarine.

Yes, a 2.3 2wd Ranger will get better MPG than the 4.0 but the driving performance of such a contraption will be so abysmally disappointing compared to the 4.0 that you might as well go buy a Focus wagon and not deal with the confusion about if it can get out of it's own way or not.

adsm08 said:

Again, as I said, if you want to work have a truck. If you want fuel economy have a car. I find the entire notion of anything that comes factory equipped with a cargo bed and a whimpy little 4-cyl engine to be absolutely ridiculous. I can see more use for tits on a bull or a screen door on a submarine.

Yes, a 2.3 2wd Ranger will get better MPG than the 4.0 but the driving performance of such a contraption will be so abysmally disappointing compared to the 4.0 that you might as well go buy a Focus wagon and not deal with the confusion about if it can get out of it's own way or not.

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Dont be so closed minded man! Just because you dont see a need for them, doesn't mean the needs don't exist. Most of the trucks bought today barrrrely get used for weekend trips to the hardware store. My truck handles that just fine, all while being twice as fuel efficient.

I wouldn't be so sure that the v6 truck is any better to drive than a 4 banger. For example, my regular cab/5 spd/ shortbed/2.3 weighs just a bit over 3000lbs and has 143hp. Most 4.0's came in extended cab trucks that start around 3600lbs, and easily climb over 3900lbs with 4wd and an auto trans. The 4.0 SOHC comes with 207hp, so my 4 banger has a very similar power to weight ratio than the vast majority of 4.0 SOHC trucks. It gets 30mpg, compared to their mid teens. And it more than handles everything that I use it for.

Unloaded my wife's old S-10, with the 2.2 2wd would spank the pants off my Ranger with the 2.9 and almost 200K miles. Both were manual. The S-10 had 4.10 gears while the Ranger had 3.45s. It also had about 75K fewer miles on it. Now one time we did use the S-10 to haul off a 1500 lb load of scrap, and she did do it, but the trip from my house to the scrap yard is mostly down hill. That truck almost didn't make it up the one hill it did have to do. The Ranger, even with the old 2.9 has done the same thing many times without a problem.

When you loaded them down the Ranger had the advantage, hands down. Since I don't have my truck to drive around and look cool and go "Hey I have a truck, look at my huge wang" I don't see the point. I have the truck to go do truck stuff.

And honestly my position on this is not confined to Rangers. I work on cars for a living, at the dealership, and nothing gets my annoyed faster (and this happens a lot) than the old man who comes in complaining that his truck rides like a truck, and he wants it to ride like a Town Car because he paid a lot for it, and it doesn't get 30 MPG, and he doesn't know why he bought a truck because he just uses it to drive to Wal-Mart once a week. So closed-minded or not, I will continue to hold the position that some vehicles are designed for a given purpose and that it is ridiculous to buy something meant for one job and hope it will fill an opposite roll well since that is what you really planned to do with it. It's like buying an impact wrench and trying to use it like a drill. Yes they are similar, yes it might get the job done (yes I've done that in a pinch when I had an impact wrench and no drill) but it really isn't the best way to do it.


Oh yeah, almost forgot. The S-10, with all it's many years more advancement and aerodynamic advantage, and such got 20 in the winter, 25 in the summer, almost all highway miles. The Ranger pulled a consistent 17.5 rain, shine, sleet or snow, highway or city, loaded or not.

Maybe driving naked will take enough weight off the truck to notice a MPG difference.

But anyways, I know where you're coming from about the I4 engines in a truck, that's why I didn't get one. Oddly enough, at the time, I was trying to decide on getting a Ranger with mid-size capabilities or a Ranger good on MPG's and more or less a base model. Obviously, I went with the first choice mentioned, but sometimes think about trading mine in for a 4-banger. I had a 1987 Ranger 2wd long-bed 2.9 5-speed that was good for what it was used for, it got close to 20 mpg and ha 140 hp and 170 ft lbs. But because of our winters, wanted 4x4 and the 4.0 looked overall better than the standard 3.0, so I went with the 4.0.

While 12 MPG is low, 16 is about the best these engines ever really do. My wife manages to get 17.5 out of her Explorer, but its all real nice highway miles.