Terrible City Mileage?!?!? Please Help..

[So Sick]

I ve only had my explorer for a couple months and have been driving it more lately and noticed in the city im getting 12mpg with a 4.0 auto. i run the AC on low and drive 'fairly" conservatively. i noticed when its really hot out when i start it the idle is sitting too high for like a minute till it drops back down. it seems to be running fine, and has no check engine light poppin up. what could be causing this poor of mileage? o2 sensor? egr? wouldnt they throw a code tho? anyway any help is appreciated!!

 

[BrooklynBay]

You still get better gas mileage than I get on my 89. I average 7-9 MPG city, and 14-16 highway.

 

[RJDriver]

If you are looking for something to tinker with.... how about cleaning the MAF sensor? Also, tire pressure..... and if you are looking at gaining serious mileage, check out Aldive's thread, "My quest for 30." Last I read, he achieved 36 mpg on the highway!

 

[snoborder42]

12 MPG in the city with the AC running is about what you should expect. Try turning off the AC and see what happens.

 

[98blk5.0]

i get 13-14 w/ the AC goin on high but i have a 5.0 with 31's

 

[bisjoe]

That's not right, I got 15 in town with A/C on with my old '96 4.0 auto, and as much as 22 freeway. Check tire pressure, and try a good fuel additive to clean the carbon out of the intake, to start. How many miles on it, have the spark plugs ever been changed? Is it 4 wheel disc or rear drum? If drum see if they are dragging. Actually even the rear discs can do that, the little parking brake shoes can hang up.

 

[So Sick]

Yeah i figured i would get way better than 12mpg in the city, hell i get that out of a heavily modified ls1 trans am that i drive hard. I bought this for a daily driver thinking it would get decent mileage but apparently not. Its a 6cyl not a big block. Thats lame.. I need to clean the maf/aic, tires are fine, 4 wheel disc and ive never heard of anything "dragging" on a disc set up. For the mileage im getting i could just get one with a 5.0 and actually enjoy it lol..

 

[Gator Jeff]

I have a 2000 sport with the OHV. If you plan on changing the plugs, you can try some Seafoam to clean stuff out of the engine before hand. I say before because if your engine is REALLY dirty, it could foul the plugs. There are a couple threads for that.

You also might want to try the TPS adjustment. I just did that and saw a 10% increase in fuel economy. The link for that is...

http://www.explorerforum.com/forums/showthread.php?t=79362

Of course, air filter, tire pressure and all the usual suspects.

For me, if I'm doing pure city driving, I usually see around 15 MPG.

 

[BryanB]

Is your 4.0 an OHV or SOHC? The OHV like I have is so incredibly underpowered that is works harder to achieve even what most would consider "normal" driving. I usually get about 300 miles out of a full tank. If you consider the Gen II Explorer tank holds about 20 gallons that equals 15 mpg average.

In fact, "OHV" in the ancient Sumerian tounge translates directly as "Exxon/Mobil's best friend"

 

[So Sick]

I just realized its an OHV so thats prob one good reason why my mileage is sucking. I cleaned everything today and ran some fuel system cleaner thru it, hoping it will help a little. I guess im gonna sell it this summer and start looking for a 5.0 4dr

 

[JohnnyO]

There is nothing magic you can do. Clean air and fuel filters, 35 psi in the tires, new plugs and maybe wires, and that's about it. You may pick up a smidge of mpg with synthetic oil and synthetic in the axles and transfer case but it won't work a miracle.
A better exhaust and a tuner like an XCal will help, but then you've spent about $700 and got to figure how long until you save that in gas?

 

[aldive]

You still get better gas mileage than I get on my 89. I average 7-9 MPG city, and 14-16 highway.

He doesn't drive a mini van ....

 

[aldive]

12 MPG in the city with the AC running is about what you should expect. Try turning off the AC and see what happens.

Thats a rather pessimistic comment. It should do a lot better.

 

[So Sick]

Thanks for all the replies, i never meant to open a "can of worms" in this thread. Im not sinking any more money into this thing, ive cleaned everything and got the tires at 35, im gonna deal with it until i find a more suitable model

 

[Gator Jeff]

Try the TPS mod! Free assuming you have access to a multi-meter and a drill/dremel. It can't hurt and I'm positive I gained a couple MPGs by doing it.

 

[97greenmonster]

Tune up! how are the plugs, wires, filters etc.?

 

[99xlt99]

Glad I saw this thread. I have been seeing the same poor mileage out of my 99 OHV as well, and I knew it was the engine causing poor mileage. I am lucky if I see 12-14 mpg in the city. Are any of the ideas in Aldive's threads worth doing on the OHV? I am sure the SOHC responds much better to those mods than the OHV does. I might just get rid of the truck if I can't get better mileage. It is my daily driver and I'd be better off driving my Cobra for how often I fill the explorer up with money.....errr I mean gas.

 

[So Sick]

i dont know about the tps mod?? Any links?? Where is the fuel filter on these?? I looked around and never saw it. The air filter and sensors are all clean. Tires are at 35lbs. Not sure about the plugs yet, i havent pulled em. Its 85k now so im sure it needs plugs if they are stock. What kind of plugs should i get for it??

99> i hear ya man, ive got a ls1 trans am and a 306 fox body that i get the same mileage in and drive waaaay harder and are heavily modded lol. I just drive this to keep the miles and wear/tear off my toys. These things are god awful in the city. Interstate i actually get good mileage!

 

[Alan]

I replaced my DPFE ($40 at Auto Zone) a week ago after diagnosing a P0401. It's really easy to do. Two screws hold it to the throttle body. My mpg has increased from 15 to 17 in town. Can't wait to see what the highway figure will be.

 

[So Sick]

No idea what that is. It revved up to over a 1000rpm when i started it once it got warm out and when i cleaned the maf and egr it made it worse (no i didnt mess up the sensor in the maf). Now it goes up to like 1200 and sits for about a minute before dropping down to about 800. Also where is the fuel filter on these things and what kind of plugs should i use? People have been offering suggestions but not really answering my questions LOL.