94 explorer, poor gas mileage. . . .

[protomind]

I have given the car a full tune up
fuel filter, spark plugs, wires, pcv valve, oil change, air filter, tranny flush etcetera. . .
I have 3.27 rear end and I am getting at the best so far 16 miles per gallon. I am getting around 13.8 average on a full tank this is with almost half highway driving.
I tried a computer diagnostic and got all 1-1-1 which means that there is no problem.
I took the car into the New Jersey state inspection facility and they hooked up the car to the OBD reader and I passed- no problems supossedly.

Any ideas? I am wits end here? I was thinking that I had a bad O2 sensor, but apparently not.

 

[SwaintaN]

I thought I was having same problem, our explorer got 15 mpg, but nothing wrong, figured it was cause i had over 209 thou miles on motor. Hints why I started the kit thread.

 

[Blacksheep Josh]

i have 260k on my explorer, never been touched except for transmission.

i've been running the v-power gas from shell to try and "clean" then engien out, and it seems to be working.

are you running off-brand gas? like from kroger or walmart or some other cheapo place?

 

[SwaintaN]

I only get reg unleaded from Speedway (points add up and then get discount on gas) or Sams Club Gas Stations, s*it their gas is always about 30-45 cents cheaper then everyone else.

 

[SwaintaN]

Oh yeah nothing on mine has ever been touched except for the normal tune ups and oil change. its a 93 explorer 4dr 4.0 v6

 

[djsk8r33]

i have 260k on my explorer, never been touched except for transmission.

i've been running the v-power gas from shell to try and "clean" then engien out, and it seems to be working.

are you running off-brand gas? like from kroger or walmart or some other cheapo place?

what does this have to tdo with anything. you didnt even state how
YOUR M PG is....

 

[SwaintaN]

His very first post says how much MPG he got.

 

[Potomac30]

Have you cleaned the MAF sensor and disconnected the battery to reset the computer?
Change the rear axle fluid, if it's a 4x4, change the transfer case fluid. Air up your tires too. My explorer came with 225 standard tires, the 235's that I have on now affect the speedo and odometer... I'm actually getting 8% better mileage than calculating trip meter/gallons indicates. If that doesn't help, well it's a 14 year old brick on wheels, at least it's still rolling.

 

[924dr4x4]

mine got really bad gas mileage till i did a full tune up,oil,oil filter,plugs,wires,pcv valve,new air filter and all,and now it gets roughly 19 mixed between city and highway,its never just city or just highway,my drivin is always mixed,but on a few occasions it was just highway and my gas gauge barely moved

 

[Alan_V]

Does the truck ssem to be running cool? A thermostat that's stuck open cools the ngine too much and the coolant temp sensor reports that to the PCM. So the PCM adjusts the mixture according to that input and you'll be running a bit rich all of the time.

 

[protomind]

I have cleaned the MAF and changed the read diff/transfer case/front diff all with mobil1 sythetic

The car does not seem to be running cool. What is a good way to tell?

However I have never disconnected the battery . . . .
BTW I just did an average and I got 12.6889mpg and this is with about 50miles being freeway.

 

[protomind]

BTW the truck has 87k on it and is in awesome condition in and out. It looks close to new everywhere and has quite obviously been meticulously maintained, so I do not think that this low of mileage is what I should expect.

 

[Alan_V]

I have cleaned the MAF and changed the read diff/transfer case/front diff all with mobil1 sythetic

The car does not seem to be running cool. What is a good way to tell?

However I have never disconnected the battery . . . .
BTW I just did an average and I got 12.6889mpg and this is with about 50miles being freeway.

The first thing is to ask if you know if the t'stat and coolant have ever been changed? If not, do so. Their cheap and reasonably simple to replace.

The gauge on the dash has not numeric value, it just displays a representation of what's normal. If your gauge consistantly reads near the C side of the "normal" range while around town, then I would replace the t'stat.

 

[cmhaah06]

its so hard to tell you what could be wrong when there are so many variables...what is ur driving still, do you have automatic hubs, if so are they properly disengaged, what size tires are you running, do you have an automatic or manual tranny, do you have limited slip...do you see where i'm going with this? just keep everthing well tuned up and keep her wheels pointed to the ground, and be happy that she runs.

 

[cmhaah06]

Potomac30, i was wandering how you learned that ur getting 8% better fuel milage? i knew bigger tires affected my speedo but i did not think it affected the mileage.

 

[fixxxer]

It doesn't but it does change the accuracy of the speedo AND odometer

 

[tmcphail]

How many miles on the 02 ?

 

[m4dc0w]

Potomac30, i was wandering how you learned that ur getting 8% better fuel milage? i knew bigger tires affected my speedo but i did not think it affected the mileage.

I had the same problem with my 97, when I went to 31's I noticed my gas milage drop about 10%.

Then I had a lightbulb moment, if my speed is off 10% showing my actual speed was more than my spedo, shouldn't my odo be off too.

After changing the VSS gear I noticed my milage came back to normal, maybe even a bit better.

-mc

 

[protomind]

Stock size tires and everything else BTW. I do not have limited slip.


@cmhaah06, I would just be happy that it rns except that I have a financially motivated reason to get better gas mileage. I am not getting what I should and I intend to try and correct it.

I am going to go ahead and do a flush and fill tommorow or the next day. May as well change the thermostat while I am doing it.

 

[Potomac30]

Potomac30, i was wandering how you learned that ur getting 8% better fuel milage? i knew bigger tires affected my speedo but i did not think it affected the mileage.

Mile markers on the interstate. For any 10 mile stretch, my odometer and trip meter always indicate 9.2 miles. .8/10 miles = .08
For every 100 miles that I travel, the odometer only registers 92. Your actual miles per gallon don't change that much because of the bigger tires, it's just that your odometer indicates that you've travelled fewer miles than you actually did. To determine your actual MPG, check your odometer against a marked stretch, figure out the difference between indicated and actual, and multiply your trip meter/odometer by the number.
For me: trip meter X 1.08/gallons to fill up. I reset the trip meter at every fill-up because the gas gauge hasn't worked in years.