I am currently having alot of problems with my F-150 with Gas milage. Recently I took a trip from Pittsburgh to Miami with my F-150 and we only got around 11 MPG there. I am not currently driving it to work all highway as I live not even a mile off the highway and I am still getting 11mpg. I tried to change my O2 sensors as I did get a code for that on the way to Florida and still I am getting horrible gas milage. I have a 1997 F-150 Supercab with a 8 foot bed and cap. I use this truck generally for hauling a race car but I haven't hauled it for a while and when I do that I get about 9 MPG. What can be causing this? I have the 4.6L engine as well which doesn't help at all either. I was wondering will a exhaust and a intake help my MPG at all? Also what is reccomended. I am newer to the Ford world as I owned a Dodge all my life. So any help would be great. And for those that helped me with the Stull billit grille install thanks alot! I finally got it in a few months ago and I love it. Well if anyone has any opinions please let me know the gas milage is killing my pocket book.
Thanks
Lorenzo & Erica

 

A couple of things. Do you have larger then stock tires? If so, did you adjust the speedo gear to compensate?

If it's all stock, how many miles? When was the last tune up? Still using the stock plugs/wires? Does it seem to have the same amount of power, driveability?

Exhaust and an intake will do little if anything for increased mpg, IMO. Some say they get better, others say they don't. Depends on driving style, other mods, terrerian etc.

One cheap and easy thing to just try is to reset the computer. Just disconnect the battery, turn on the head light switch (this just makes sure it 'sucks' all the power out of the system), wait about 15 minutes, turn off the head light switch, connect the battery, start truck. Don't touch the gas pedal or anything. Just let it idle the way it wants to for the first couple of minutes. Take it out for a long drive. Try to vary your speed some. Take off a bit 'harder' then you normally do, make sure you take it out on the highway and give it a good run. Keep it out of OD for some the time too. This just makes the computer 'think' you drive this way all the time. It'll adjust itself accordingly and then when you do drive "normal", you should be able to tell a difference.

Might not make any difference at all, but it's a place to start. Then you can start throwing parts at it until the mpg gets better or you go broke Just kidding, of course.

Just FYI, I get about 14-15 mpg on average. Most of my miles is highway too. I get 10 when towing.

Good Luck!

 

I have two 4.6 Ltr. F-150's in my family. One gets 17-19 gals. per mile on the freeway, and the other gets 11-15 with city driving.
Before you invest in expensive mods. make sure that all the little things are taken care of (ie. gas filter, oil/filter, tire inflation...just general maint). Once you've eliminated those obvious things take the next step.

Good luck, and let us know what happens.

 

You didn't say if it is a 2WD drive or a 4WD truck. Lately my truck 5.4 Supercab with 4WD has been getting 13.2 - 13.6 mpg. You may want to check the MAF to see if it is dirty, also check the air cleaner. You said you tried to change the O2 sensors but never said if you changed them or not. I would think that maybe both pre-cats sensors should be replaced, but before doing any parts replacement, it might help to have the truck plugged into a dealers computer and see what the computer tells you about the engine. May help before you just guess on what's causing you lack of mpg.

 

I just had two tankfulls of lower mileage because I forgot to check my tire inflation.

 

Check PCV valve, vacuum connections, tire pressure, EGR valve, run some injector cleaner through it, and that should take care of it.

-Flea

 

how's the air filter?
I've seen engines run like crap because they were starved for air.
you could also try putting in a bottle of fuel injector cleaner and a tank full of high octane gas to try clean out the injectors.

 

Redline Sr-1 or Chevron Techron are two remarkable products. I have used both at different oil changes with great results. If you use a good quality gas...there should be minimal gunking in the fuel system. Still good to do though.

Ask Navi Man...he know a lot about Techron!