My ranger has like 28 in oversized tires but I don't know if that's really the problem or if my gas gauge is just stupid..but I don't have a "heavy foot" and i go about...80 some miles on a half tank...

 

ouch.. how many miles does the truck have? It could be in need of a good tune up, along with changing the fuel filter, etc.

 

It's got 114 thousand...Yeah i was thinking it might be the filter but of course at the time when i tried to explain that to my mom i couldn't remember that damn word...filter...filter...lmao blonde moment...

 

how sounds like you just need a total overhaul... plugs, filters, everything... alos check your exhaust becuase when mine broke i dropped to close to 14-15 mpg and since i fixed it, im at 130miles with 3/4 left give or take a few 1/16 per the gas gauge which is usually really close...

 

my truck is a 4.0, has steel wheels, 32's, brushguard, rollbar is a 4x4, (basically heavy stuff) and i get around 15 mpg. like mentioned earlier, it's time for a tune up.

 

Hmm how much is a tune up?

 

I have a 98 3.0 4x4 32" a/t's 4.10s. I get around 13.5 to 14mpg. I used to get a little bit better mileage so I replaced my fuel filter, spark plugs, and wires and it has made no noticeable change. I have no CEL on right now but was wondering if one of my O2 sensors could be bad even without the CEL. Then you said to check your exhaust and I remembered that mine fell off not too long ago. I have stock exhaust manifolds and pipe back to the cat and then a flowmaster single in dual out muffler. Both of the exhaust pipes rusted and fell off. Basically my muffler is single in and just two holes in the back. Beside making my truck loud and annoying could that be causing my poor mileage as well? If so can I just weld a couple 90 degree pipes to the back pointing down? Would that fix the noise and the mileage?

 

The muffler won't make a bit of difference in your gas mileage if you clamp/weld on some short downtubes like you mentioned. All this will do is direct the exhaust gasses down instead of directly backwards and ultimately wont effect backpressure or flow. To make the truck quieter, you need to direct the sound somewhere else other than under your bed where it resonates very annoyingly into the cab. This means welding on some tail-pipes that exit under the bumper, or some side-pipes to exit before the wheel well.

You've started working on the fuel economy problem, but just need to finish the job to notice the effects of the plugs and other stuff.

Start by disconnecting the negative terminal to your battery. This will give the capacitors in your PCM time to discharge and erase the previously "learned" settings.
Using an Electronic Parts Cleaner (CRC makes some - available at most auto parts stores) clean all the sensors along your intake system. This includes your MAF (first sensor, by the filter) IAT (closer to the throttle body), IAC valve (ON the throttle body) and TPS.

After you get all the sensors cleaned and dry, install a new filter and reconnect the battery. Start the truck and let it reach a steady idle, then leave it to warm up. Once it's reached optimum operating temperature (middle of temp gauge), take a drive and give the PCM time to re-learn the driving habits, fuel curve, and other necessary bits of data.

When you fill up next, put a bottle of Lucas injector cleaner in. This combined with the clean intake system, smooth fuel delivery, and fresh ignition system will combine to increase your mileage!

 

Depends on what you replace. But without looking up prices on everything I would put it right around 100 bucks.
A tune up (to me at least) includes: new plugs, wires, distrubtor cap and rotor (if equipped), fuel filter, air filter, pcv valve, and use some Seafoam in the intake. If you haven't heard of Seafoam, check it out. There was a thread in Off Topic, I believe, a few days ago about the stuff.
You might also consider changing the o2 sensor, not sure how much they are but usually not more than 35 or 40 bucks for the most part. When those get cogged up they can wreak havoc on your mileage.
Good luck :

 

if hes missing all that piping then hes loosing loads of backpressure... the only thing diffrent in my truck pre exhaust fix and post is the fact that the exhaust is fixed.... and im driving even harder then i did before because i have power back...

 

Keep in mind that there are things other than a tune up that can cause poor milage.
A slipping trans or clutch, dragging brakes, or a severely out of align front end will all reduce milage. A bad thermostat will also lower you milage quite drastically, if the engine doesn't reach full operating temp, your milage will suffer greatly.

Does the temp guage reach the Normal mark? (Usually they read about 1/3 to 1/2 way across the gauge when warm).

If all else looks fine, and if you either don't know or if it's been a long time since a major tune up, I would start there first. Like stated above, new plugs and wires, new fuel and air filters, and a new pvc valve are all part of a tune up.

Also, is there any sign of the check engine light on? (Also make sure it's working and that it lights up when you first turn the key on).
Does the truck run the same as it always has? Did it ever get better milage?

The 114K miles shouldn't be too much of a concern so long as it's been well maintained and not abused.
Which 6 cylinder engine do you have? Manual or auto trans? (If it's an auto trans I would be more concerned about the trans with high milage than the engine).

 

Try doing a more accurate test than just looking at the gas gauge. Ford had a TSB on fuel gauges. Mine never got fixed and it too goes down fast, but then slows down.

Fill your tank up. Use your trip mileage. Set it to 0 miles and drive for 100 miles or so and fill up and see how much gas you actually used. Then you'll have a better idea for sure what your actual mileage is.

 

Saying you go 80-miles on a half tank means absolutely nothing by itself. Have you done the calculations to figure out your true gas mileage? I'm affected by the fuel-pump sensor TSB and because of that I do 100-miles per half-tank reading. I can then go well over 150-additional miles before my low-fuel indicator goes on.

 

FYI, ford has to invent a fuel gauge worth it's wait in possum crap. The only accurate way is to fill up, reset the trip odometer, and drive until you need to fill up again. Divide the mileage by the gallons pumped for your actual fuel mileage. Do this a few times to confirm accuracy.

 

Yeah I know I've been doing the trip mileage guage and so far a whole tank gets me about....215 ish...

 

I changed my spark plugs, fuel fitler, and fuel pump (the Ranger was sick) and coil and I am getting 18-20 on a full tank (18 Gal). And that includes my lift, tires, and suspension.

 

12mpg city 14highway, and I'm starting to be proud of it lol!!

 

whats wrong with that gas mileage.. and your worried about going to college and back with that kind of mileage.. sheesh

haha.. ouch buddy. Think she has you beat though.

as for the mileage.. there is lots of great suggestions. plugs, injector cleaner, fuel filter, air filter, sensor cleaning. all part of the normal maintenance really. cost--I dunno maybe 100$ plus gas to the nearest autozone (but sounds like that could be the expensive part)
iain
also. my 98 4.0 gets about 340 a tank (tank is 19.6 gallons, I put in about 18-18.5 usually). and im on 32s. you got stick shift?? if so granny shift it helps.

 

wish i got 18mpg i have done everything and replaced everything i can with the best stuff out there. best for me is 16mpg once in a blue moon normal is 14-15 and lowest has been 6mpg last winter lol so it is the weather gas and what you have put into your truck that makes up what you get for mpg and remeer the winter aditive and cold air is more dence so your engine will work harder to get the right mix it needs with the air also. i just dont think about it anymore lol

 

I already know what I have to do to get it back up. 1st) Find a way to get the check engine light off, we are 95% thinking that the computer is sending bad signals. 2) Put a muffler back on and replace all three o2 sensors. 3) lay off the gas lol!!

 

What should I try first? I am still getting poor gas mileage.

1. Put pipes back on the output of my muffler
2. Check o2 sensors (they are expensive, after I remove them from the truck how do I test them?)
3. Use seafoam through gas tank and brake vacuum hose
4. Replace PCV

Thanks,

Marc

 

I'm not exactly the most experienced here, but I'd say the SeaFoam. Go pick a couple cans up for $20 bucks and see how much it helps. It's the cheapest and it's just a good idea in general.