2004 f-250 SD supercab 5000 miles lariat. I am only getting 12.9 Best highway city does not matter. Does this sound normal??? sounds like a lot of other are getting pretty good mileage... any thoughts???

 

Any mods? Big tires? Is that unladen weight? Sounds low.

 

Where do you live, flatlands, mountains....

 

Looks like he's in Michigan. 4x4 or 4x2? I don't want to assume this, but I take it it's a 6.0? Auto or manual?

 

Is your mileage hand calculated or from the overhead console? The overhead computer is not very accurate, but usually errors on the optimistic side of mileage results.

Are you from a northern climate? If you are from a small town or get fuel from a less frequented station, you could still be running #1 winter diesel which would result in lower mileage also. Kind of grasping at straws here, but stranger things have happened.

 

How are you calculating your MPG.. Manually or do you have/use the overhead?? Is 12.9 the best you can get out on the 'open' freeway..No traffic/commute to affect the highway MPG?? Try and give a bit more 'stats' so we can offer up some simular conditions/MPG's... Any driveability issues (Cold/Hot).. Any extended warm up times ect... Alot of variables to concider to calculate 'Good' mileage.. Mine is about 14-17 city/highway


..........................HP...................... ........

 

-I live in michigan outside detroit.
-flat terain
-6.0L Automatic trans
- 4X4
-mostly city driving
-No mods completely stock.
-Not sure on the fuel

The overhead has never improved above 12.9 but has dropped to 12.7. I tow a 27' trailer on the weekends to local race track tongue pull 6500 loaded. This is when the mileage average goes down. I have calculated mileage by hand also, run the tank dry fill with 30 gallons and drive to empty best 13.2MPG

other issues
clear vision off
Pulls left
A/C suction hose leaks
Clunks (Unkown, been in twice NPF getting worse)when shift from 2nd to 3rd gear
clunks when on and off acceleration
whines while in 4 wheel

Other than these issue I love the truck and the power, most important the ability to pull the trailer with no hesitation!

 

Also no +power in the trailer wiring

 

I also live just outside of detroit. I was getting about 13mpg and I started using stanadyne performance formula fuel additive. this increased my milage to about 14.0. then I added a juice module with attitude monitor (just last week). this morning, on my way to work, I was getting 15.5 on the highway (I 96). I hope this helps

 

I do not mean to sound....well..........how do you drive it, T/H mode all the time, are you conservative at the starts, how many different folks drive it. Do you idle for long periods while hooking up the trailer, do you back up allot with the trailer. Most race track you sit in the pit lane waiting to get in for 20 minutes, does that happen, sounds a bit weird but if you do it every week...

There are so many variables to know about just you and your truck.
Keep giving us data.

 

Tim and others have made some good points as to 'where' the fuel may be going... But,, I'm still a bit unclear as to wheather you've done a 'empty' (no/short stops) highway/flat road only trip?, and then hand calculated your MPG.. And, filling 'totally' up the neck.. (don't mean to be insulting I guess were looking to see your "ideal best", than see how much is being 'gobbled' up when towing or in city use.. I know mine will take a bit of time to get the last 10.00 or so into the tank after the first click... It kinda seems to be like a 'trophy' to get over 20MPG, and mine falls short at 17.. Two trips.. I know I could get better mileage if I slowed a notch or two, no A/C, no stops, but kinda hard to do.. Haven't towed the heavies 'yet'..

..............................HP.................. .............

 

Bone stock F-250 PSD 04/04 Build date 4/28/04 - delivery date 5/10/04
3.73 - 5 spd auto - Lariat - Just returned from 2nd 2500 mile trip within a month. 5500 miles total - 5000 on Interstate.

15/17 City 19/21.5 Hiway 14.7 pulling a 5k Boat and trailer. manual computations.
Overhead indicates slightly higher by 1.5 to 2.0 avg MPG.
Interstate speeds at 70 or less at 2000 rpm's or less. The one time I kicked it up to 75 for about 250 miles, I noticed a significant drop in MPG down to 15.5/16.0. My engine is a March 04 build.

No leaks, squeeks, unusual noises that's not self induced.
Breakin period - by the book - and no towing until after 1000 miles.
I've been extremely careful about buying fuel and only at high volume dealers when at all possible. No noticeable water accumulation.

One thing I found, right off the bat. The last 3.5 to 4.0 gals of fuel takes a good while to get it full to the neck. I had one stop where it was cold, wet and rainy when I was fueling and didn't get it completely full. The next time I computed the fuel, it gave me some ridiculous number of 25 + MPG.

So far - The F-250 is giving me that same satisfaction that my ole '78 F-150 4x4 with 285,000 miles did before I archived it.

 

Didn't see where anyone suggested this, but sound slike you are using the overhead...
and sounds like you are NOT resetting your overhead periodically or have never reset it ?

NOT that the overhead "lie-o-meter" is accurate, but typically they are WAY over optimistic in all that I have seen....

the only thing I can think is that if you never reset yours and idle a LOT, like I do mine with the remote starter, wel....
burning fuel and going zero miles makes for a very poor average mpg !

my 8K+ excursion gets a realistic 15 to 16 mpg around town even hot rodding it like I do with the Diablo Predator....

 

Good call I forgot about that one and it can easily be the culprit

 

Your mileage should improve. At 5K miles it is probably not even close to being broken in. My parents diesel improved on mileage up until about 35K and Tim told a story a while back about someone he knew that saw improvements up to something like 70K miles.