I did a search but I can't seam to find info on a list of things to do/clean to make sure I'm getting the best possible gas mileage.

 

My experience over 150,000 miles and using a monitor.
1. Tires as hard as you can accept the ride.
2. Road speed between 50-60 mph.
3. Train yourself to always apply the lightest throttle you need to just keep the truck moveing. Back off throttle after going over top of a grade down the other side. It's a habit to keep throttle on that costs gas.
4. Gas with no or low Ethonal.
5. No A/C/ Defrost unless you need it.
6. Fresh front Ox sensors and spark plugs.
7. Thermostat running the motor at 195 to 200 degrees.
8. Run at the lightest weight. Tail gate weighs about 55 pounds.
9. Oil speced at 5w20 and do not overfill. If kept at the lower part of the add oil crosshatch area the motor will be a bit livelier.
The low end does' not' mean the motor is out of oil but you have to keep on top of it every week to be sure..
There are no real helps from air intake or exhaust mods, for the costs involved.
Under the above conditons there is more than enough air in and exhaust capacity out with the factory equipment unless the cats are getting restricted..
Good luck.

 

Keep in mind all the items listed above will make life painful for maybe a +-1 or 2 mpg difference. The absolute best way to get mileage out of that truck is to sell it and get a Honda Civic. Seriously though dude, you are not going to find gains of significant (5+) mpg improvements no matter what you do with this truck. Might as well accept that, live with it, and enjoy it for what it is! If mileage is your main concern, you have purchased the wrong vehicle. Any money 'supposedly' spent for the benefit of fuel mileage will never be reconstituted, even if you kept that truck for the rest of your life.

The only item above I have no idea what he's talking about is item 9. How on earth does running the quantity at or near the lower end have any effect on the mileage or the "liveliness" of the motor?? The only concern with oil quantity is running it to a point where the crank is splashing in the oil, causing foaming. But then if you've got this going on, fuel mileage will be among the last of your problems. Below that, I don't see how it can possibly make an impact; unless you are debating the weight of a quart of oil over the grand scheme of things…in which case I'll run mine plumb full thank you very much.

 

Thanks guy's...
I know about gas mileage, I also own a Jeep
I was just looking for info to make sure I'm getting what I should be getting. If 14mpg is what I should be getting than I'm ok with that, but if I should be getting 18mpg, I need to fix whats wrong.

 

You are getting 14? City, highway, or mixed in what ratio? Is your odometer verified accurate? What are your driving habits? How many miles on it and what is its maintenance history? I assume this is the truck in your original post:

Okay - which engine, which transmission, what axle ratio? What size and type tires? Any mods (lifted, intake, exhaust, etc.)?

For reference, my truck (see sig) gets about 15 in the city and 18 to 22 on the highway.

 

I have not gotten over 11mpg. 3.55ls w/ 33" tires. Progammer as well. Don't be complaining man.

Take Bluegrass's advice. I've read hundreds of his posts on different forums and have yet to see him be incorrect. He's great at diagnosing across the net as well.

 

Yes I could have put a little more info

Let's see, everything on the truck is stock. The tires are 265/75/16, fuel was mix Hwy/City and I'm mostly a Sunday driver.

My brother was surprised when I told him I was averaging 14mpg. Did notice the check eng light is on....maybe O2 Sensor is faulty. Don’t know if that would increase fuel consumption. I do need to get the computer on it to see what codes come up.
I do plan to get a K&N filter and change oil.

 

K&N filter won't do anything for you.
If your mileage consious consider this;
At low throttle opening such as cruise and normal driving, the throttle plate is the sole gate of air into the motor not the filter.
Raising air flow capacity for 'normal' truck and driving application offers no benifit.
Only time is at high rpm and wide open throttle where airflow becomes affected by flow losses in the intake system.
.
CEL lamp on, get the code/s read and post them.
The codes do not tell you what parts to change, only the system in trouble.
Then you look for the cause before replacing any parts.
Good luck.

 

Just so you know....I'm not mileage conscious (my second post), I just wanted to make sure I'm getting what I should be getting. (as for fuel consumption)
I'm with you on getting the codes checked first.
Again thanks for the help.

 

'03 FX4 w/ 5.4L and Running gas w/ ethanol around town I see right around 11 usually.

If I run NO Eth. gas (can only get it at one store here in town) I see right at 12mpg around town really easy.

On the HWY with eth. gas I saw 16ish, I have not made a run on the hwy long enough to get a good estimate on non-eth. gas.

 

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You didn't answer most of my questions.........take it from the top, please.

 

I get about 14 combined most of the time. Thats the best it does other then all freeway trips. I've done all the maintenance and every thing. Best I've gotten was on a trip in montana I got 18 out of a tank doing 80 on the Montana high plains..

 

4.6L V-8
4 speed Automatic
No mods on the truck (6.5) box
Couldn’t tell you what the axle ratio is
Bridgestone Dueler 265 75 16

Hope this helps

 

What is the AXLE code on the door jamb sticker? its 2 alphanumerics - example, H9.

Maintenance history = how many miles since the last spark plug change, etc.