gas mileage situation

[general lee]

Hey everybody,
this gas mileage thing is killing me on the highway.I can understand the not so good mileage in town, but am only getting 18-19(at best) on the highway. So far I have added Flowmaster exhaust, KKM filtercharger, Mobil1 synthetic oil, and new plug wires. Really thought that would help. I noticed that the 93-94 Explorers were rated at like 23-24 mpg on the highway and was thinking they may have changed something? I just saw that some of you got better gas mileage on th highway so I was wondering if maybe I could try an accomplish that too(Especially when gas is so friggin expensive). Thanks to everyone in advance.
Lee (1991 explorer 130,000miles, new tranny)

 

[S.Matsushige]

Your rear gear ratio may also have a hand in determining what kind of mileage you get, coupled in with your driving style and the type of driving you do. I also have a '91XLT. I have a modified air box with K&N, Bosch P+4, Splitfire wires, Ultra-flo SS muffler, Superconverter, Borla headers, 2.25 inch pipes, 3.73LS rear, 5spd trans standing on 31s. I do mostly highway driving usually without the ac since its cool in the mornings and evenings when I drive. I average between 19 and 21mpg uncorrected. Uncorrected since I haven't compensated the speedo gear for the 31s I'm on. This means I actually get a little better than that. 18-19mpg I think is very good in my opinion. There are a lot more members here which only get 14 -15mpg. Anytime I can get 19mpg, I consider myself lucky. Besides, mpg and how you measure it is very subjective. I could fill my tank up to the filler neck on the initial run and drive then just fill to the first click on the next. But because the initial fill allowed me to go far and divide that by not doing the exact topping off on the next fill, my mpg would be awesome. I say you are doing okay in the mpg catagory. How much is gas there? Its about $1.75 a gal here for regular unleaded. On the outer islands of Hawaii you'd be look'n at near $2 per gal for regular unleaded. Hope this helps.

[This message has been edited by S.Matsushige (edited 05-20-2000).]

 

[DannyB]

18 MPG??? 19 MPG??? ARE YOU KIDDING????? I can only get 15.7 MPG (that's averaging) on my 1996 4.0 4x4. And I have basically stock, except for tires, 255x70x15. I wonder . . . What's everyone else getting????

 

[Ray Hutchinson]

Re; Gas Mileage!
Hey, I'd love to get 18-19 MPG!!! My '93 has the K&N, Dynomax hi flow cat back (Muffler and 2.5" mandrel bent pipe). Jet chip, 3.73 " tow package gearing, and 31" BFG's and I'm closer to 15-16 mpg highway, 12 around town, but my Expl isn't my daily driver, its the toy. The observation about driving habits is right on, also check for proper tire inflation, and brake adjustment. As for the air, chip and exhaust mods, they don;t help with mileage that much, just improve performance. It's just physics: more energy out (speed and performance), requires more energy in (fuel). Of course, a little more efficiency helps , but generally, more air in requires more fuel to keep the ratios correct, so you get more power, worse mileage! At least that's my experience, and my mechanic agrees. Talk to Paul B., he gets about 6-7 Mpg Highway with his Vortech blower etc! Nobody said wheelin was a cheap hobby!;-)

Ray
93 white XLT
slightly moded,
Lotsa radios

 

[ERIC]

Ray, I will second your comments about mods not doing much for gas mileage, but fine for performance. I've done the Flowmaster Catback, airbox, and K&N. Mileage stayed the same, performance went up.

And General Lee, the mileage is just about exactly what you are saying you get...about 18-19. Well, if i'm **real** careful, maybe I get 20, but it's been almost a year since i saw that.

------------------
ERIC H.
'96 XLT
"You can run, but you can't hide...my dogs track."

 

[FMNavajo]

I'm sure we can all appreciate getting anywhere from 17 to 20 mpg with an explorer/navajo that has more then 100K miles.

This might help as there has been many subjects about mpg on this site.

If you've made mods to the air intake and exhaust and still not getting good mpg switch your attention to the fuel and electrical system. Changing the fuel filter at regular intervals will help. Manintenancing the intake manifolds, (Check the torque of the lower intake manifold and re-torque if neccessary), keeping the throttle body clean will help. Checking the battery and cables weekly will save you alot of trouble on the trail. The battery cables on the early models run all the way under the engine and are subject to heat, oil, road hazards, and all the wheather you drive through, not sure were the newer ones run, I'm guessing the same.

If you want to go all the way like I did you might want to go this route, by doing this I improved my mileage by 7-10 mpg, I had 140K+ and I was getting around 11-13 mpg (it sucked big time!).
Check your #5 plug and see if it has any carbon build up, if so, compare it to another and see if #5 is worse. If it is check your oil fill cap and see if it has some brownish, tanish build up inside it, if so, your having some lower intake manifold gasket leakage and thus letting radiator fluid mix with your oil.
Cure - get the following parts and plan a few hours on a weekend;
Intake manifold gasket set
Valve cover gasket set
Some intake or throttle body cleaner (about 4 cans spray type)
A couple of sizes of soft wire brushes (speeds up the cleaning process)
Fuel Pressure regulator (if you haven't changed it in the last 60K miles)
o2 sensor
Might as well get a thermostat while you have everything else off, and it's a really good idea to have a haynes or chiltons manual to do this because there are specific torque sequences to follow while reinstalling the parts.

You'll need a torx socket to get the fuel rail off, and metric sockets for everything else.

RELIEVE THE FUEL PRESSURE PRIOR TO DISCONNECTING ANY FUEL LINES! (see chapter 4 in your manual)

After you remove the uppper intake manifold, fuel rail and injectors remove the valve covers and lower intake manifold, (cover the heads and block with a towel or something and find a place to start cleaning parts).

You'll want to get all the carbon off, my parts looked new when I reinstalled them.

Clean any gasket material that is still in the engine as best you can without letting anything drop in the engine, use some small rags to put in the ports.

This whole procedure is in the manual, much more detailed, but it's there.

You can also do a search on gas mileage and get a ton of related threads.

FM

 

[DCider]

Well, I guess I shouldn't post my last milage check. I took another trip to the Redding area from San Jose and back over the weekend. From SJ (505/5 intersection) to Redding my milage was 21.69 mpg. Return split from Redding to the 505/5 intersection was 23.43 mpg.

My speed up was pretty close to 75 mph (90% + of the trip) and the return trip was split with maybe 60% of the trip at 75 mph and the rest at 80 mph with the A/C on during the return trip.

I've never gotten this good milage when the Explorer was stock. I believe that the best milage increase I got was after the header install. This may be a situation where all the mods made the best efficiency after the headers were installed. YMMV.

 

[Alec]

The mod that made the biggest difference in mileage for me was the computer chip. I now get 17/24 with the mods listed below. Of course, I do use 83 octane, but the increase in mileage it gives me outweighs the cost. I still run fine on 89 octane, but get about 16/22. Hope this helps!

 

[roadkill]

wish I got 18-19 mpg!

Boy, I wish I got 18-19 mpg. I have an EB, 3.73, K&N filter, 31's, and I get lucky with 17-18 mpg. With the weight of the xplr's, it's not gonna be an econo car.
Good Luck!

 

[PunkChild]

Hey, you guys are lucky! I have JBA headers, Borla cat-back, a K&N drop-in with a modified airbox and some other stuff and I am lucky if I get 10 mpg. I also have a maunel tranny which is supposed to help, but it only makes me run the RPM's up higher.

 

[2mrchio]

83 octane?

Where you find 83 octane? Or do you mean 93? Yeah, that makes more sense...