i need all the suggestions i can get. when i bought the truck i was getting 14 miles to the gallon, now im down to 8-9 after less than 1000 miles of driving. 302, auto, 3.31 gears, 31x10.50 tires. i changed the fuel filter and air filter and pcv valve. where else should i start looking? would my cats being clogged have that much effect on it? or are the tires too big for the gearing? it sucks when im getting the same gas milelage as my buddys dumptruck with a carburated 460 in it

 

If tou put the big tires on it then that is a major factor that brought it down, the gears don't like the big tires. I hate making that choice big tires or good gas milage, it sounds like you have another problem also but cats usually take quite a while to get backed up.

 

Recalibrate your speedo(psom) there is an article in the tech article section. and go to tirerack.com to find the specs for your tires. I did on my 94 made a big difference

 

Also check for any error codes. Ford engines typically get pretty poor mileage when an error code is present.

 

if i bumped up my gear ratio to 3.73s or so to put everything back in factory spec, would that help? since it would be running at optimal performance....

i had plans of going straight axle and 9 inch with 4.56s and 35s or 36s but thats on hold right now if im getting this kind of mileage....

 

Your gear/tire combo is probably not the cause, unless you changed the tires yourself, and saw the mileage drop after that. There have been a few posts regarding calibrating speedometers lately. Give yours a check, it could be off a bit if your truck came stock with 235/75 tires. Poor mileage can be caused by any number of things, but start with the easy stuff and make sure the tires are inflated properly. Low air pressure in the tires can literally suck the gas right out of the tank. Well, not really, but it seems like it.

BTW, where did you get the beautiful girl riding shotgun? I've looked in all the catalogs, and can't find one listed anywhere.

 

>Your gear/tire combo is probably not the cause, unless you
>changed the tires yourself, and saw the mileage drop after
>that. There have been a few posts regarding calibrating
>speedometers lately. Give yours a check, it could be off a
>bit if your truck came stock with 235/75 tires.

yep truck came with 235s and i put on 31s. going up 2 inches in height i don't think would make my mileage drop from 14 to 9 though.
i also started having the problem after my front fuel tank was replaced because it had a leak in it. since then i changed the fuel filter but like i said that didn't help much. i also have begun to notice my fuel pump being louder than normal. if i stand next to the truck i can hear it running under there. is something wrong there?


Poor
>mileage can be caused by any number of things, but start
>with the easy stuff and make sure the tires are inflated
>properly. Low air pressure in the tires can literally suck
>the gas right out of the tank. Well, not really, but it
>seems like it.

yea they are aired up good.


im wondering could it be a problem with the computer making it burn much richer than its supposed to?



>BTW, where did you get the beautiful girl riding shotgun?
>I've looked in all the catalogs, and can't find one listed
>anywhere.

its a secret. the good ones worth taking for a ride are getting hard to find these days.

 

[updated:LAST EDITED ON 01-14-03 AT 09:47 PM (EST)]No but it will give you an accurate base line as far as what kind of mileage you really are getting. If you are off a few mph's so is your odometer. Also do you live where the use of oxygenated fuel is used in winter ?? Makes a difference for me mileage wise.

 

i baught a 94 with a 5.8 in sept. it was getting about 15 mpg it droped to about 8-9 was losing power also it was the cats replaced them now get about 16 mpg good luck

 

im gonna redo the entire exhaust first chance i get well see if that makes a difference. could the be with the engine burning way too rich because of a sensor or computer problem?

 

what doy ou have to do to check error codes? what kind of error codes might be found that would gas bad gas mileage?