MPG that is.
I'm the proud new owner of a 00 Navigator. I'm not so proud of its mileage, though. In the month I've had it, I've averaged 11.4 MPG. This is done by dividing the miles driven on that particular tank by the amount of fuel added to fill it up. I will note, that I never top my tank off anymore. This is generally a waste of fuel from my investigations, so once it clicks off, I'm done.

My inspiration for all this is because of a person on the Explorer Forum. It has been his undertaking for the last couple of years and he regularly gets over 30MPG with his 2WD Explorer. I will also note, that I tried to link his posts on there an lost everything I wrote (bummer). So if you would like to read it, email or pm me and I will send you the link. Its very long. You can also search for it. His thread title is "My quest for 30" My other inspiration is $2.50+/gal fuel

My wife drives this to school almost everyday. I'm pretty sure she doesn't use the "egg under foot" technique, since I ALWAYS notice the mileage has gone down after she has it. This will make it harder to reach my goal unless I can teach her to do the same.

Last week, I purchased all new tires and had it aligned. I bought Hankook dynapros after reading Consumer Reports' claim of having the lowest rolling resistance.

Wind resistance:
Lets face it, these trucks are like a fancy brick driving down the road. Not aerodynamic at all. Improving on this will be difficult and probably the largest factor in the poor mileage these things get. Of course the weight doesn't help. So, tonight I will be removing the cross members from the roof rack. Not only should this help with mileage, but reduce some of the wind noise at highway speeds. I did this to my Mazda Protege5 I used to own and couldn't believe the difference, especially the noise. Any other ideas?

Internal fluids:
Next will be the switch over from regular to fully synthetic fluids. Here, I could use some help from you all. I priced it out at Napa for some Royal Purple (not my first choice) and Oh My! This will be a pricey undergoing, but I think it will be worth it. I welcome any advice on brands, types and weights I should use to help improve the mileage.

Bolt ons:
Exhaust, Intake pulleys and Chips. This will be the most expensive part of this. This will also be the last portion I do because of the price. I will need lots of help here. I am very unfamiliar with the different brands that are out there and which ones will actually help me with my goal.

Tune ups:
Almost forgot about this. My truck has about 87,000 miles on it right now. I have no idea what has or has not been done, so I will assume nothing. This will be quite an undertaking, from what I've read, to change the spark plugs. I don't know what else to do for a tune up on these trucks since I've never had to do it before. I believe they are coil over plug, so there's not cap and rotor to replace. Again, any helpful advice on this would be appreciated.

Additives:
I've heard lots of good things about Seafoam. I bought a can already and put half of it in while i had less than a 1/4 tank. Not sure if it did anything, though. I still have a slightly rough idle at a stoplight. It's fine when in park.

Fuel:
We can't forget about this, can we? The 32valve 5.4 takes 91 octane or higher. This is pretty expensive stuff. It averages 20 cents higher than 89 octane. Ethanol is added only to 89 octane here so it actually makes it cheaper to buy than 87 octane. I've been putting 89 in with no evidence of knocking or pinging. I did this with my last Navi and didn't have a problem at all either. I will be trying the 91 in the next few tanks, though, to see if I get better results. Ultimately, my goal is 20 MPG. Is $6/tank extra worth it? We'll see.

I'm sure I'm not the only person out there that would love to have a truck like this, but get better mileage. So I welcome all comments and advice you have to improve our vehicles mileage. Not only should this net us better MPG, but more performance as well.

I will keep posting on here with the changes I make and the results I get from them. Please feel free to do the same. If I can find a 4x4 dyno around here, I'll try to make some runs on it once in a while too.

If 20 comes easy enough, I will try 25!

Sam

 

mpg has been talked about a lot on these forums...i'm sure you can average 20-25mpg in your AWD 5.4 navi if you do all you've said AND pull out all the interior, put on a few sizes too small tire (it'll look better on your speedo - but wont really help anything much), and ONLY drive on the freeway going approx 50 mph (sans a heavy head-wind)!

not to seem too skeptical...but if you do ANY city driving or like to exceed 65 mph it ain't gonna happen - esp if your baseline is just over 11mpg right now - some of these trucks seem to get inherently better mpg (at least, according to their owner's reports) yours (and, unfortunately, mine) doesn't seem to be one of them.

good luck nonetheless, and let us know what improvements you do find,

al

 

I have a feeling, that if I can figure out what is causing the rough idle at stops, I will gain at least 1-2 MPG. I will be making a trip to MN this month. About a 800 mile trip. This will give me a great baseline for my highway mileage. I will be keeping it at 65-70 the whole way. Speed does indeed kill mileage, so I might try the first tank at 65 max to see what the difference is. Cruise control will be used, of course.

Sam

 

rough idle seems to be a pretty common problem - might want to try a search (i've got no suggestions myself).

i can get about 16-20 mpg on the freeway going somewhere in the 55-65 range, above that it drops under 16, and i've got the 5.4 2wd with 3.(33/13? - can't recall right now) gears.

make sure you reset your mpg computer before your trip so you can get an accurate trip reading (though i guess you'll probably just be calculating that manually)

some people on this forum have said the sparkplugs can wait till 100k (i think that's what the manual says as well - chilton's/hayne's says 60k).

i've tried driving my truck without exceeding about 1.6 rpms around the city for improved mpg and noticed somewhere in the 1-2mpg imrovement range. but i can't stand that, so i've gone back to the heavy foot.

 

Air resistance increases with the square of speed. So you'll want to keep it at about 45mph or so for max MPG - just below the point where airflow starts to rise. I made that mph number up, but I'm sure it's right around there.

 

Well, I have the 4.6l in my Expy (I know, not the same, but I think this is relevent). I used to get ~12-14MPG with mostly city driving. I could squeeze out 15MPG on roadtrips (usually heavily loaded down with snowboards on the roof.
I recently bought the SCT Xcal 2 with custom tunes from MotorHaven. I just completed a 2500 mile roadtrip using the 91 octane tune and averaged a little over 18MPG for the trip. So the extra cost of the fuel was made up by the better mileage. Since you have to run =91 anyways, I think this will definately help increase your overall MPG's. But as far as seeing 20MPG, I agree with the above recommendation to strip the enterior and drive only at 45 MPH. I

 

Well, I'm not sure I can justify stripping everything to my wife and 5 kids. I'll have to keep everything in there, I guess

 

God bless you my son.

I actually did acheive 22.5 MPG ONCE (or perhaps it was 24, I don't remember but it was noth of 20). I was coming home from work, the roads were iced, I maintained 45 MPH (or so), and I had a tailwind. It can be done!

 

Just got the oil changed in it. It's got Motorcraft 5w20 in it, so maybe that will help. Sure seemed to run better afterwards. Just looking at the computer, tells me it has improved, but we'll have to see what it averages out over the next few tanks.

Removing the roof rack cross members sure did quiet highway speed noise. Much quieter! I wish I could remove the main parts of it without having to fill holes in the roof. Oh well, something is better than nothing.

hkiefus, thanks for the blessing. I now feel like I can proceed.

 

I am anxious to see if removing the roof rack bars helps out at all with mileage on your truck. I might have to try that on our next roat trip.

 

Roof rack isn't really in the air path at highway speeds. Try taking out the windshield and opening the hatch.

 

I beg to differ. Wind noise has reduced 10 fold since taking them off.

 

It may be a stretch getting 20 out of your Nav, but you could trade it in for a Toyota Hybrid Prius. You can get a fully loaded one for about 13k. It can get about 40 some mpg. LOL Just messing with you. I've been trying to think of some ways to get a little better mpg. I may switch to full synthetic oil and see if that helps.

 

There are to many variables from what part of the country you live in, to how far you drive. For instance I just moved and my commute went from 17 Mi to 6 Mi I could not belive my milage went down 1.5 MPG. So many things can change your milage good luck in your 20MPG.

2000 5.4 EB
K&N FIPK intake
12.6 MPG

 

Maybe strip the wife and leave the kids behind, maybe it will rekindle the romance and forget about the mileage for now.....