my 95 7.3 e4od, here's the scenario. i replaced the fuel lines from the front d/s frame rail on up unhooked the batteries and such as i did a starter swap also. the truck reliably knocks down 14-15 mpg in town and 17-18mpg on the highway (3.55 gears) i made a run yesterday to pick up a car and put 14 gallons in it and went 162 miles and used it all up. something is seriously wrong!!! ??? the truck runs fine and i didn't notice any excess smoke or anything. any input would be great as this truck is slated to go to iowa 1200 miles round trip and 11-11.5 mpg is not gonna cut it. thanks, pete

 

Believe it or not...it may be fuel quality. Especailly If this was for only 1 tank full.
I have noticed big MPG differences from one tank to the next.

You could try fuel additives or a little 2 cycle oil in the fuel. Some report higher MPG's.

 

In addition to this, you can try adjusting your driving.
If you accelerate at 3-5 mph/sec, you'll see a big jump in economy, as well as try to keep it at 65 on the highway. these things have the aerodynamics of a brick.
I'm not exactly sure how to check this, but you may want to make sure your brakes arent dragging.

 

i drive like i always do. i'm not a lead foot. actually the brakes are "loose on the rear of the truck" so that isn't it. the truck just sucks fuel all of a sudden i havn't changed anything. i always run howes additive. ?????

 

Me too, I'm getting tired of hearing all this great mileage from a lot of people, dodges and chevys too. The more mods I do the better my truck runs but the mileage always sucks, 10-12mpg. It doesn't seem to matter that much if I'm pulling or not???

 

FPR screen. Pull the FPR off the outside of the filter housing and clean the little screen that's in the hole where the FPR attaches to the housing. It's amazing the difference that this will make. Several MPG if it's really bad.

 

try a different fuel station. despite the prices, i prefer Chevron for the very high minimum Cetane rating. (48-50)
truck stops may be under 40.

 

Im in the same boat, BUT I use PEMEX Diesel, so it could be the culprit, the records for the original owner (USA) where 18-20 MPG. and now I have 11-12.5 MPG, towing or not, and I cleaned the screen, checked the sensors, 2 cycle oil etc, etc. I want to ask to the people who lives close to the bordeline and is using PEMEX DIESEL how is the MPG? and what kind of PEMEX DIESEL: UBA or not UBA?, here in my Tow, there are not UBA diesel yet.

 

is your diesel ulsd?

 

PEMEX DIESEL UBA = ULSD. I dont use that only LSD = NOT UBA.

 

What sensors did you check? How much two cycle oil is good and what kind or brand?

 

i've been running off road, but for the last few months i havn't been. ulsd that's what's at the stations. i cleaned out that little screen and there wasn't much dirt in it. would a pinched fuel return line cause poor mpg? i'm not saying that's the culprit just a possibility. what about the turbo flapper? the exhaust control valve not functioning properly. it gave me that code when scanned, so i wired it open and i'm driving about 31/2 hours and i'm gonna see how it does. later, pete

 

X2 try another place to get your fuel, do you buy fuel there all the time? could be some price gouging going on or their pumps need to be calabrated.

 

1. Yes It would. It's equivalent to a plugged FPR screen.

2. EPBV (Exhaust Back Pressure Valve). If it was stuck partially closed it woul have a negative effect on your MPG. You can disconnect it electronically.

Take a look at this link for more info, scroll down for pictures.
https://www.ford-trucks.com/forums/7...bled-f250.html

 

I checked the MAP and the EVP sensors. I blend 1 oz per gallon of diesel. Look for an assless 2 cycle oil, no matter what brand.