1999 17 mpg/2001 14.1 mpg

[Marv02]

I had a 1999 EB 4X4 back in 2000 it got 17/18 MPG up on the HWY which was Good in my eyes when we traded it it it had 1400000 miles on it.

Now I have a 2001 EB 4X2 for about 2 months now me and my wife like the the MPG not all that great it all stock and it get 13.5 MPG compaired to our 1999 we use to have any idea why it has 102000 miles on it.

I maxed out the tire pressure 40 PSI to gain some MPG but that did not help much.

I dont drive it hard at all no rabbit starts it a cruiser ONLY.
Same 5.4 engine the 1999 was 4X4 so I know it weight more so why is the 2001 eats more gas.

Oh ya the 1999 never blew a plug but my 2002 F250 did LOL but the F250 got 10 MPG on a good day going down hill with the wind behind you the 38-14-18 Inch tires killed the MPG even it was regeared for it..

 

[tonydiv]

40 psi ????

If you really need to get every last mpg, why in the world did you get an Expedition?

 

[Marv02]

40 PSI thats what the tire sidewall said it safe.

I just wondered why my last Exp got better MPG anyways I drive my 435 H/P 505 T/Q 1986 Corvette as my every day driver thats get 24 MPG on the HWY and 15 City combo of 20 MPG.

The Exp is for weekends when I take out the family in untill the weather turns bad then I park the Vett until it get nice outside agin.

Yes I knew going into the Exp it not made for High MPG but 3 to 4 MPG diffrence between the 99 and the 2001 why.

You would think the 4X2 would get a little Better MPG not less.

40 psi ????

If you really need to get every last mpg, why in the world did you get an Expedition?

 

[98EBEXPY]

Maybe it needs a tune up

 

[alaskanexpy]

yeah how many miles, when were the plugs last done?


i've never seen better then 15.1mpg on the highway. that was ONCE so i dont feel so bad for ya lol normally its 13-14mpg.

 

[toms89]

Your 1999 Expy was doing well and at the high end of the scale for gas milage. That said I do believe your 2wd expy should be doing better all other things being equal . As was already said I would give it a tune up 1st. Air/fuel filters and plugs.

 

[Marv02]

I will change out the plugs and see what happens.

Everything else already have done I just Nervous about plugs with these heads what I read when you change plugs thats when they start blowing out plugs.


I make sure I use Anti Seize Compound and touqe them to spec's.

Then keep a very close eye on them.

 

[DF5.4]

What gears are in the truck? What was in the old truck? How's the alignment? What kind of tires are on the truck?

Plugs, filters and fluids are a good place to start. I would run the tires at the recommended pressure (probably around 35 psi). What little it helps mpg will be offset by replacing the tires prematurely because they wear out down the center.

 

[Marv02]

It has Dunlop tires on them there half way worn out I planning to replace them in a couple months anyways so I dont care if they start wearing in the centers.
Alingment seems good but when I buy a new set of tires I have it checked then.
New trans fuild had theat done the 2nd day I owned the car oil changed and coolant change at the same time.
Installed a extra trans cooler.

I have not got around to the diff fluild yet but that on my to do list.

Same for the Brake fluid.

I have know Idea what gears are in it when I change the diff fluid I read wats stamped on the ring gear and see what it said or count the ring and pinoin teeth.

I want to it keep it stock I already have a Frankenstien car that no where stock dont what anouther one it fun but it nice to just go to the auto store and get what you need with out trying to tell the stupid person behide the counter it will not work on my car I need this instead.

And they tell you thatt not what there computer telling them whats in the car LOL go though this all the time.

What gears are in the truck? What was in the old truck? How's the alignment? What kind of tires are on the truck?

Plugs, filters and fluids are a good place to start. I would run the tires at the recommended pressure (probably around 35 psi). What little it helps mpg will be offset by replacing the tires prematurely because they wear out down the center.

 

[khpony]

I have a 98 w/5.4 and it get's 13.5-14 in town. Hope to go to Colorado in October and then check highway mileage.

 

[jacks3am]

I like th 99 engine better they had forged pistons and a forged crankshaft! but that isnt somthing that should effect mileage, I say tuneup, new fuel cap, gotts mod, and LONGTUBES!!!!!!!!!!! lol jk about the long tubes

 

[JDMitchell]

What gears are in the truck? What was in the old truck? How's the alignment? What kind of tires are on the truck?

Plugs, filters and fluids are a good place to start. I would run the tires at the recommended pressure (probably around 35 psi). What little it helps mpg will be offset by replacing the tires prematurely because they wear out down the center.

Bingo!

I bet the older one had 3.31 gears and the new one probably has a 3.73 in the rear. Higher rpms and needing a tune up = less mpg.

 

[2000eb]

do not use antiseize. use ford motorcraft spark plugs and get a tq wrench and tq to specs and you will be ok. do not use anti-seize

 

[toms89]

I like th 99 engine better they had forged pistons and a forged crankshaft! but that isnt somthing that should effect mileage, I say tuneup, new fuel cap, gotts mod, and LONGTUBES!!!!!!!!!!! lol jk about the long tubes

Only ford mod motors that came with forged pistons are ones that left the factory with factory superchargers. All others use hypereutectic pistons. Hyper pistons can have tighter tolerances as they expand less than forged. This is the reason they use them. They just wont take the abuse that forged will. Many of the 1st gen expys did come with forged cranks though. The weakest link on the mod motors are the cracked powdered metal rods and they are safe up to near 500 rwhp.

If you can find a link for longtubes from the manufacture (for expy) Please post it.

 

[Marv02]

Why do not use Anti Seize on the plugs.

I have Good TQ wremchs already.

do not use antiseize. use ford motorcraft spark plugs and get a tq wrench and tq to specs and you will be ok. do not use anti-seize

 

[JDMitchell]

Antiseize could give the plugs more of a chance to shoot out. These motors are very tempermental about plugs and torque values. I haven't shot any yet, but it has happened to plenty of owners.

Sent from my Droid via Tapatalk

 

[toms89]

There are many opinions out there on what is the proper way to change plugs on these motors. I have heard pros and cons of using anti sieze compound on them. I personally did use anti sieze on mine. I think of anti sieze more as an anti-corrosive than a lubricant. Keeps the dissimilar metals together from corroding the aluminum threads. Its just one of those rules I have always followed with aluminum heads. But its one of those damned if you do damned if you don't things with these particular heads..

I can tell you I had almost 30,000 miles on mine since plugs changed with no issues.

 

[Sven]

My 2000 4x4 Eddie Bauer gets High 13s low 14s in town. Long hwy trips at 60-62mph I get 17.5 - 18.5 mpg and have seen 19-20 with a tailwind.

Combonation City/Freeway/Hwy I get 16 minimum when taking a 400 mile trip with hills/city/and interstate driving.

I`m in a very flat part of the country, so that probably explains why my expy is great on gas.

But even towing a 21 foot aluminum trailer, with a side x side and 1 atv on it I can get 10-11.

 

[walnuts4x4]

pshhh.. mpgs... I get 11s city and almost 13 on the highway....

but I did not use anti-seize and Autolite Double Platniums when I did mine and so far all is good