I used to own a 1996 Mazda B4000, manual transmission, 4.0L, extended cab 2 door, 4x4 and would get 15.5-16 MPG around town which I thought was pretty good.

A few months ago I bought a 2003 Ford Ranger, auto, 4.0L, 4x4, hard shell tonneau cover, extended cab 4 door, with brand new standard sized tires P245/75R16.

When I first got the truck I was getting 10-10.5 MPG around town.

After Googling, and reading many posts on this site, I:

1) Verified that I was using good driving habits for mileage (I was/am)
2) Inflated the tires to 42 PSI (versus the default 35 PSI)
3) Replaced the air filter with a new one
4) Cleaned the MAF sensor
5) Cleaned the throttle body
6) Installed new spark plugs
7) Ran SeaFoam through a couple of tanks of gas
8) Seafoam treated the engine via the intake/vacuum
9) Ran Startron through a couple of tanks of gas
10) Verified that the brakes were not dragging
11) Verified no codes produced in the onboard computer
12) Keep the climate control in "Vent" mode so the A/C does not run

All of this helped, and I am now getting 13.0-13.5 MPG around town, however this is still about 2 MPG less than what I should be getting with this truck. The truck was rated at 15 MPG from the factory in this configuration and from other posts it seems many people are getting the factory specs, often better.

Have I missed any of the obvious things to try?

Are there any other suggestions (other than "get a Prius" :-) )?

Thank you,

-Dj

quit beating a dead horse.

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2001 Ranger Edge 4x4 (sold)
2006 F150 Lariat 4x4 (sold)
2007 Explorer XLT (Destroyed by Deer on highway)
2014 Explorer XLT (inherited from parents)

If you are that worried about gas mileage that you need that extra 2 mpg you shouldn't have a truck that only gets 13mpg. I really am not trying to be a jerk or anything, but it's a truck with crappy fuel mileage, there's a lot of other variables as to why you aren't getting the extra 2 mpg

\.=.

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It was rated 15 from the factory in perfect condition on a dyno. Considering its almost 10 years old, I would consider yourself lucky only losing 2 mpg...

\.=.

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I guess I should have asked, "Does anyone have any HELPFUL suggestions?" :-)

Seriously, plenty of other people with 2003 Rangers post on this forum that they get factory spec or better gas mileage with their 10+ year old trucks, so it is not completely out of the realm of possibilities that I should be able to get the same.

I'm looking for helpful suggestions as to what else I might look at to figure out why mine is different (ie, identifying those variables mentioned).

One possibility that I've found is to replace the regular oil with synthetic at my next oil change.

Others?

Thanks,

-Dj

How many miles are on the truck?

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Just over 98,000 miles this week.

-Dj

Do you have alot of accessories? like tool box tools etc. try lighting your carring load maybe take off spare, tire jack and replace with can of fix a flat. See if any of the oxygen sensors are sluggish or not reading right. Do the throttle cable mod maybe your robbing the engine of some much needed air? Is the weather nice? cold air can be a factor if you live up north. Try keeping overdrive off in town driving helps the transmission out too.Check to make sure thermostat is not stuck open

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2003 XLT FX4 Level II
Painted skid plate, Pioneer double din, painted radio bezel/door handles, headlight mod, throttle cable mod, Gibson cat back, afe cold air, 06+ fender badges, Remote start, 06+ mirrors,06+corners, 35W DDM HIDs 4500k head and fog lights,polished alcoas

Upstream 2's are part of the 100k tune up along with plugs and wires. Reset the computer after change them.

How are your front wheel bearings? I got a 1mpg bump after putting on a new one. Also change the front/rear diff gear oil.

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99 x-cab 4x4 4.0l auto
mods, cranked t-bars, silencer delete, k&n drop in, Trans Go stage 3 shift kit,3200stall Fuddle Racing Torque Converter,
VANIR 63mm TB, Roush split rear exit exhuast, E-Fan, JBA headers
Auto up/down both windows, OHC, EATC

03 Crown Victoria Police Interceptor

The main difference between your old 4.0 and your new 4.0 is that the old one was a manual.

Manual = Better mpg's

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The bed is empty except for the tonneau cover. No toolboxes or anything else like that.

How would I test the O2 sensors? Sounds like a reasonable thing to do, and I can see where that might affect mileage.

I think the thermostat is fine. Engine temps are normal, and if I put the heat on high it will melt your toes. :-)



What are "Upstream 2's"?

Two years ago a new ignition harness was installed. It still looked in "new" condition when I changed the plugs a couple of months ago, and I checked both ends of each wire to ensure good connections. The engine runs great with no sign of any issues, but I know that doesn't always tell the whole story.

It just passed a state vehicle inspection a couple of months ago and I had to replace an upper arm on the left front, but everything else looked good at the time, including the bearings. If there is no play I'm not sure how else to tell if the front wheel bearings are bad or failing.

Rear diff oil was changed at that time (replaced the rusty rear cover with a new one), and the front diff oil looked clean so it did not get changed.

Thank you both for the suggestions! You've given me a few more things to look at.


One other thing that occurred to me was a partially plugged catalyctic converter. There are three on the truck, but I have no idea how to test these or tell if they are good/bad/marginal. I assume, possibly incorrectly, that if they were going bad I'd get an engine code.

-Dj

The heat melting your toes has no bearing on the thermostat working they are intended to fail in the open position but that doesnt always happen but if its open all the time the truck will take a long time to warm up and stay cooler longer thus buring more fuel cause its working harder. 02 sensors you have to check by computer to see if they are sluggish, which can happen with out throwing a code. Or just replace them and hope for results. cats could be clogged i would try to get a lower milage one from a junkyard maybe the cheaper option.

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2003 XLT FX4 Level II
Painted skid plate, Pioneer double din, painted radio bezel/door handles, headlight mod, throttle cable mod, Gibson cat back, afe cold air, 06+ fender badges, Remote start, 06+ mirrors,06+corners, 35W DDM HIDs 4500k head and fog lights,polished alcoas

Also you might want to see what the computer tire size is set at, at the dealer maybe it had something else on it at one time and your current tire size is throwing off the miles and you only think your getting bad MPGs

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2003 XLT FX4 Level II
Painted skid plate, Pioneer double din, painted radio bezel/door handles, headlight mod, throttle cable mod, Gibson cat back, afe cold air, 06+ fender badges, Remote start, 06+ mirrors,06+corners, 35W DDM HIDs 4500k head and fog lights,polished alcoas

Upstream o2's are the pre cat sensor that are responsible for fine tuning air fuel ratios.

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99 x-cab 4x4 4.0l auto
mods, cranked t-bars, silencer delete, k&n drop in, Trans Go stage 3 shift kit,3200stall Fuddle Racing Torque Converter,
VANIR 63mm TB, Roush split rear exit exhuast, E-Fan, JBA headers
Auto up/down both windows, OHC, EATC

03 Crown Victoria Police Interceptor

I had an O2 go bad. I just replaced all of them so I wouldn't have to go under there for the others at a later date. I also replaced the TPS and IAC as they are fairly cheap. Make sure your MAF is clean. There's how to's for all of that. After all that and a general tune up, I get great mileage(for a 4.0 Ranger). Also check or change your fuel filter if it hasn't been done in a while. It may not do any good, but clean fuel is happy fuel.

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1999 XLT 4x4 extended cab, 4.0L, Autotragic , 207+K miles. Fog light mod, Throttle cable mod, cargo light/blinker mod, Cruise control light mod, LED floor lights, black Ford emblems, Sony head unit, pioneer speakers, off brand 400W amp, Kicker C10 sub, custom enclosure, locking gas cap. Replaced every damn sensor on it. Hankook Dynapro ATM tires.

I clean my MAF every oil change, about 5k miles. Also, I keep the rpm below 2250-2500. My mileage is in my signature.

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2005 XLT 4.0 4x4 Automatic 5R55E 4 door
Avg. mpg: 18.2 Best mpg: 19.76