I am not having any luck with the forum search option, so I am sure I am asking a question that has been asked before.


Is there any way of getting better gas mileage from my 5.4L Expedition (without stating the obvious; changing rear gears, losing weight off of it, not driving it at all, or buying a Honda)?

I could care less about the gas milage, but my wife is the one that drives it and she thinks that 13-14 city and 18 hwy is not good enough, so for her sake, I am asking the question.

I was not sure if things like aftermarket exhaust or air filter kits or things like that really worked for saving gas.

Anything would be helpful,

Jeremy

 

Unfortunately you shouldn't expect much out of a vehicle the size of an Expedition. An exhuast sytem and air box will help somewhat, but really won't be that noticeable per tankfull. You will hear exagerated claims of mpg gains on here, but I think a lot of them are just wishful thinking. Myself, I've just learned to accept it and realize that I didn't buy my Navi to be an economy car.

 

Rustman: Those are fairly good numbers that you're posting, especially for a 5.4. I wouldn't imagine you would ever see much better than that in the real world. Sure, you could set the cruise on 45mph....running downhill......with a tail wind.... I'm faily happy with 16.5 mpg in mixed driving. Good Luck.

 

rustman,

I did the simple k&n change and did not gain anything noticeable. short of major mods, which could be fun. I think she is just going to have to get used to it. FWIW a client of mine wants to trade in her CRV for an expy. I reminded her of the mileage, she told me the CRV was not much better.

 

I did a FIPK, GMS MAFS, and Gibson Super Truck exhst on my 5.4 Screw

I get now a solid 16 in general...as long as I keep my foot out of it. In general is mostly Chicago rush hour *driving* or should I say 3 lanes of parking lot in a line. <g>

I put in a vac guage, and when driving I try to keep it above 10 in/Hg, and that does it.

When I WOT, the vac gauge drops to 1 in/Hg in a heart beat...so I think the millage goes the same way.

I do get really bad millage when I tow a tandem axe Well Cargo trailer, but that is a 7.5'x16' and when it is loaded, it is like pulling another truck with you.

People can claim that this is BS all they want, I have the lack of gas bills to back it up. If they never tried the whole thing...they would not know for themselves.

With or without mods, alot of this depends on how it is driven, if you wife mashes the pedal to the floor when the light changes...more mods will just make the problem worse, as the truck will go faster yet.

Let it breath, take the back pressure off the system, and you have a good start.
For all those with the " you loose tq by taking the back pressure off the system"...I don't even notice the loss, even with towing. If you could tell the tq loss on a 5.4 with the SOTP dyno....your butt is a whole lot more sensative then mine, and I guess you are towing a whole lot mroe then you should be with a F-150.
Also I don't street light race...another reason not to care.

 

Thanks for the replies guys.

What most of you have said is more or less what I have told my wife, "It is a people hauler, not a econo box. You are suppose to get bad gas mileage." And for what it gets, it is not that bad. The 13~14 is just city, and the 18 was just hwy on a long trip with the cruise on and the AC off.

I will propably try the intake and exhaust anyway. With that said, do you all have any recommendations for a intake system (system or just a filter) and a cat-back. For the cat-back, nothing too loud, that is my wife's only request.

Thanks again,

Jeremy

 

I have heard good things about the Gibson. It's not suppose to be very loud and will help slightly with the performance. From what I recall, it's also reasonably priced.

 

I have a gibson super truck on mine. I think that might be louder then what the sife wants. You could try the side swept exhst, either in single or dual ( refering to the one that exists behind the rear wheel, not the rear exit itself ).

As for the airbox, I currently have a K&N FIPK, but I am swaping the airbox out for the JLP airbox, with 2 3" brake ducts in the bottom, being fed from the air dam.

I do notice sitting in traffic in 100* temps that the truck will not get out of its own way, when drawing the heat in the engine compartment. Once it is moving it is ok.

You could look at the Volant, but in my book this is just alot of money for *almost* the same thing as stock, using the stock fender draw point. I thought part of the FIPK was to increase the amount of air that a stock filter could draw, to allow it to breath ?

The Ice-Man intake I think uses the stock airfilter box, and a different tube to the T/B.
I have seen a few posts when people mod the intake side of the stock airbox, and ream out the hole size in the fender, I'm not that brave <g>.

You could look at a step one, by replacing the stock filter with a K&N and adding the brake duct hose down to the air dam or behind the grille to holes cut in the stock airbox, if you wanted to try a lower cost cool air system.
In the end I think some type of FIPK is in order to get the most bang for the buck in letting air into the engine.
I now will have a K&N filter that I cannot use with the JLP airbox <g>.

Check out ROUSHFAN-1's intake his is the same style off the L, with the JLP airbox. I tried several times to make a heat shield for the K&N and everything that came off my metal brake looked like crap, so this weekend I gave up and today I am going to order the JLP airbox. Don't know how much better this will be, I am in experimenting mode right now.

The other thing that made a world of difference on the accel is the GMS MAFS. Taking out the stock MAFS was actually more of a help to the engine then I thought. I don't need to mash the pedal as much to get it movign the same.

Another item you can look at is the electric fan kits. I got the Flex-a-lite 270 kit, others I have seen are getting the new Performance Products fan kit. This takes ~ 11# of rotating masss off the front of the engine, that made the engine also rev quicker / easier.

I have a fiar amount of money into my truck in engine mods, and I don't know how long it will take in gas saving to pay for it, I think last time I calc'd it is was 65k miles to recoup the mods cost in gas savings.
The reason I did the mods was first for my hobby, and some what perf gain, the gas savings was a side result, and I calc'd it just to be curoius.

Check around see what other opinions you get, and mash them all together. The truck might be more fun to drive after just a few mods, so be prepared for the first few tansk to be less, from mashign the pedal down. <g> And if the wife does nto change the angle of the throttle, it will drink more gas in the end, how you drive it stock or modded has a big impact on mpg.

 

Rustman: As for the exhaust question, my wife actually likes the sound of ours. If you bury your foot in the carpet, you will hear it...but it sounds nice. At 70 -80mph, it is very quiet, hardly noticeable. After 80, it sounds even better, the faster you go.....you know, staying up with traffic...ha ha. I would do it again.

 

I did the "po-mans" mod to my stock airbox (hey I just got a dremel kit with a bizzilion pieces) with K/N filter. Came out great and a smiidgen more ummph. So far it sticks at 14.7 mpg, and I do get on it.

Like everyone else said, your pushing a 5500lb box. Just close your eyes when you fill up. I find the hood mods coming out interesting. Especially the ram air design.

 

I only dream about 14/18...I'm more like 10/14 in my '00 5.4L 4x4.

 

Tell the wife that those are prety good numbers and to relax.

As far as 'MODs' that will help you do better don't count on much. Even if someone can give you a majical intake/exhaust/chip whatsit that actually WILL increase your mileage by 20% (none will) for $1000 it would take you years and years to recover the upfront cost of the 'MOD'

If you want a little better performance and have a budget of $1000-$2000, get a chip, a CAT back exhaust, do the po-boy intake and be happy if you get a little extra mileage to go with you increased performance. Just don't go expecting to buy 'MODs' to increase fuel mileage, they just aren't made and the payback wouldn't be there if they were.