I have a 96 f150 4x4 w/302 and E4OD tranny that i cannot get above 10mpg no matter what i do. If i drive it hard or baby it...winter or summer the mpg will not budge from 10 which is starting to kill my wallet. I love this truck and have plans on converting to 4x4 with a lift and everything but with the bigger tires i don't want my mileage to drop anymore then it is now. Im out of ideas here, ive done tuneups, o2 sensors, k&n w/ f250 intake, catback exhaust, high flow cat, cleaned egr no vacuum leaks that i can tell, ive done seafoam etc and nothing works. Anyone got any magic tricks that i dont know about yet or is it time to trade er in for a diesel? would a maybe 192 degree thermostat help? i think i read that on here somewhere...

 

The metal tube for the EGR commonly rust out. Also, the vacuum can also rots through(but you cant see it untill you take it off). Have you checked your vacuum? What about fuel pressure? Checked for codes? KOEO and KOER codes can tell alot. That is definetly horrible mileage. You should have atleast around 16.

 

What gear ratio does the truck have?
Have you looked into possible brake dragging?
How is the compression / mileage on the engine?
Is your transmission slipping?
Do you use tires of larger diameter than stock?

Also, have your Fuel Pressure Regulator checked.

 

i got 86.5k miles on the truck right now... the truck has 3.55 ratio and im running 31" tires but this didnt affect the mileage at all from stock. how would i check to see if brakes are dragging or if the tranny is slipping? the only code i found was banks 1 and 2 running lean but i reset the computer and havent seen it in a few miles.. i havent checked the compression or fuel pressure yet, prolly going to go buy a gauge tomorrow. the fuel pressure should be around 35-40psi correct? also the egr tube was replaced not even a year ago and as far as i know all vacuum is fine, i sprayed ether on all the connections that i could see and no change in idle was noticed. i also pulled the vacuum line off of the FPR and didnt smell/see any gas in there

 

For what I can tell, your engine should not be worn out since it has low miles, but every engine is different. My 1995 5.0 4x4 has 170K miles and I get between 15 and 17 MPG depending on how heavy my foot gets.
Regardless of the mileage, it is a good idea to check compression. You may find premature wear. Do the engine consume oil?
Brakes dragging would be fairly easy to spot. One or more wheels would be significantly hotter that the rest after a relatively short drive. Another way to know would be to take advantage of one of those free brake inspections that places like MIDAS or Brake Masters offer from time to time.
The transmission slipping would feel like power is not being transferred to the wheels...like you have to rev the engine a lot to get the truck to pick up speed. it usually happens more in first and second gear.

Another possibility that came to my mind is a malfunctioning TPS.

Hope this helps.

 

well the tranny defintely isnt spinning as the truck has plent of power down low..ill pick up a compression tester tomorrow, what should compression be? ill also check the brakes and as far as the tps goes, i replaced that about....4k miles ago

 

Have you checked the timing yet? Bill '95 F150 4x4 Super Cab Eddie Bauer (5.0 Auto 3:55 Gears)

 

Check the fuel regulator first. Hopefully its that since its a cheap and easy fix.

 

i had a friend check my timing and it was set at 10*btdc...i checked the fuel pressure today and it was about 29psi with key on and only dropped 1 psi after 10 mins, with engine running it was about 32psi and if i pull the vacuum line off of the regulator it jumps to 42 psi which im assuming means the regulator is ok?

i just filled up today and it ended up coming out to around 13-14mpg which i think is really weird as i havent done anything different...im gonna check the compression tomorrow and replace my t-stat with a 192* one. to check the compression u pull out all the plugs and go 1 cylinder at a time right?

 

Yep, easier on the battery that way.