5.0L AWD in search of better MPG!

[fastcougar]

I have a 97 5.0L AWD Explorer with roughly 76,x.. miles. It has the stock R15 tires (unsure of h/w ratio) with the Limited Slip 3.73 ratios (front & rear). I average 14MPG city and 17MPG highway, which is good considering the age/mileage of the truck and those are the manufacturer numbers to the "T". However, with gas prices on the rise and me moving farther away from family (will involve more highway trips with the Ex this summer), I'm wondering what I can do to increase the gas mileage.

Since increases in power through N/A normally mean increase in mileage if you can keep your foot out of the gas all the time with the newfound power, I have been considering the following mods:

Torque Monster Headers (header flange is warped and it has a slight leak)
New Mangaflow Cat-Back
MAC Intake
Full Tuneup (plugs/wires/pvc/etc.)
Regearing the diffs to 3.23???

My Ex has the tow package and I will soon be periodically towing a car to the track about once or twice a month. So, what do you think will help with the mileage & also be acceptable for towing.

 

[410Fortune]

regearing to a lesser ratio is a BAD idea, it will take more RPM's to get you moving and up to speed.

Youcan go all out and convert to a selectable transfer case, that will pay for itself in the long run (2wd option)

Or yuo can do little things like preventive maint, tune up, tire pressure, etc.

 

[TheJMan]

I've got a 5.0 AWD and the biggest gain in MPG was from my MAC intake. I gained around 1 to 1.5 mpg just with that. I've also done a few maintenance items that have helped about .5 to 1 mpg. They are:

- New Autolite Double Platinum Plugs
- Synthetic Gear Oil (I use Royal Purple 75W-90)
- Synthetic Engine Oil (I use M1 0W-20)
- New PCV Valve
- New DPFE
- New fuel filter
- Tranny Pan Drop and Filter change (use Mercon V)
- Tranny Flush

I hope this helps. I used to get 12 miles per gallon before I did all this and now I get 14 mpg.

Since you have a warped header flange, I think the Torque Monster Headers would be a great benefit. You'd probably spend more than the cost of the headers taking your X to the dealer to have them put on a new exhaust manifold. A good catback system would compliment the headers well. You could buy a Gibson or a MAC for around $250-$300 and put it on yourself, or you could go to a muffler shop and have them custom build a system for your. Whatever you decide to do, good luck!

 

[bwinterroth]

I've got 5 words for you... Chevron Techron Fuel System Cleaner!!

 

[plrs x45]

Hello. 17mpg is good. This may not be an option but my former boss sold me her car because she has had a company car for 2 years. I got a 95 altima loaded with leather, moonroof, and good stereo for 900$. Did I mention it has 71k in the odometer? I love driving my X. I just got smart and bought a second car. Good luck with whatever you decide.

 

[IAmTodd]

I've squeezed 19 our of mine on the highway. But I think thats about as much as you're gonna get. Maybe 21 on flat ground. But you have a V8 powered 2 ton truck with AWD, prepare to pay out the bum for gas

 

[Lizard]

I have a '99 Limited V8 AWD, and just went from 17-18 mpg,(hwy) to 22mpg by changing my throttle position sensor, and making sure that the voltage on the new unit was set at .96volts (although I'm running at ~ .97v) Do a search on how to do this. Sorry can't remember the name of the thread off hand. It also cleaned up a slightly rough idle, and the infamous "pinging" under load.

 

[fastcougar]

Hello. 17mpg is good. This may not be an option but my former boss sold me her car because she has had a company car for 2 years. I got a 95 altima loaded with leather, moonroof, and good stereo for 900$. Did I mention it has 71k in the odometer? I love driving my X. I just got smart and bought a second car. Good luck with whatever you decide.

Look at my signature ... I know all about getting a car with great gas mileage. However, my 05 Corolla sucks at driving in the snow and more importantly towing my Cougar to the track. Each car in my stable has a defined purpose.

I will be moving 68 miles from work ... the Corolla is strickly for commuting to work during the week.

I will be moving within 15 miles of a 2 mile 10 turn road course ... the Cougar is strickly for fun on the weekends

I have a 2 year old son and a wife that refuses to drive a station wagon ... the Explorer is for everyone

 

[Al Rapp]

Get manual locking hubs for the front. Everything in the transfer case will still be turning but not under any load. The rear will do all the pushing & the front will free roll. When necessary lock it up for AWD. I have a 1996, 5.0 ,AWD Eddie & will do this in the summer. My friend that is an ace mechanic told me it will help. Lucky me I'm getting 9 - 10 mpg in the city. I hope it will help us both. The Eddie is tuned well & blows perfect emmission numbers.

 

[Mbrooks420]

There's no auto hubs to swap out for manuals on any of the V8's. Consider sythetic, or at least new fluid in the axles, tranny, t case. A summer touring radial will give a good highway ride, and has lower rolling resistance than an all terrain.

 

[Jester1994]

I have been thinking of what other mods I can do to increase my mpg and power as well. As you can see from my signature, I have the usual, exhaust, intake, chip, but also bigger tires and usually something carried on my roof. I get 14-15 mpg highway usually, which is not good, even for a 5.0 AWD. MY headers are warping, as I can hear a leak even more than the usual ticking on the 5.0 passenger side I have learned to love and live with.

So I think that some Torque Monster Headers maybe in order to boost power, fix the leak and increase fuel economy, if the results I have read on this site are proven by actual members on this site that install them. Other than that, I guess I can change the diff fluids, since I assume it's never been done (I bought it at 62k, now 102k and I never did it). I'll probably swap the PCV valve this spring and maybe change the wires since the plugs were done in the fall.

There's not much we can do, since we are trying to push a 2 ton brick down a highway or up hill against wind, etc. with a thirsty V8.

 

[aldive]

A few other things that will help you are:

synthetic fluids thought
synthetic wheel bearing Greece
better computer tune ( chip )
higher air pressure in tires

good luck ....

 

[Jester1994]

A few other things that will help you are:

synthetic fluids thought
synthetic wheel bearing Greece
better computer tune ( chip )
higher air pressure in tires

good luck ....

Thanks Al, I'm meaning to do the synthetic diff fluid, I already run Mobil 1 oil. Also, I feel that my Apten chip tune isn't doing what it used to anymore. I feel taht with my Pro-M MAF and other mods I should feel more power....I feel I used to get more, and with my not so good mpg (14-15), I want to improve a tune and power again. I used to run between 40-45 in my tires, now I lowered it to 38-40 front/rear and I didn't notice much of a highway difference.
What's the easiest way to do the wheel bearing grease?