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horrible mpgs

9K views 42 replies 23 participants last post by  7.3l-2-6.4l 
#1 ·
so here's the deal I've got an 08 6.4l f-250 fx4 3.73 rear and i can't get better than 10.4 mpg empty on the highway, 9 in the city and 6.5 towing. I use my truck for everyday driving but on the weekend i tow about a 11,000lb trailer. the truck has around 17,000 miles and mpgs haven't really changed since it was new. I keep my foot out of it so i don't know what the deal is. i took the truck to the dealer a few weeks ago and they reflashed with the latest update but since then mpgs have gone down. the truck doesn't regen but about once a tank which i was told is normal. i have an afe stage 2 intake. i'm running out of options and i'm looking for the best mpg's. any help would be great sorry for the long post. thanks for any help
 
#2 ·
The reason your MPGs are bad is because its a 6.4L
 
#8 ·
thanks for your helpful replies... go back to the 7.3L forums. I'd bet that with a tuner and dpf delete the 7.3 would be wishing to have our mileage. And its not because its a 6.4L, i see right at 14 highway and 11 city, and that is with 37's
 
#6 ·
if your dealer finds out ya they will void your warranty but just put everything back on and load your stock program on and the spartan tunes are suppose to be untraceable....I know other guys on here have received warranty work after doing it....what the dealer doesnt know wont hurt them....I was getting 8.5 stock and now getting about 15 with the 275 tune so it was a good jump for me.
 
#7 ·
should've gotten a CTD (please hold the floggings) I LOVE PSD's but you can get a CTD 6speed with 3.42's in the rear. I am a loyal ford guy and will never own anything but (probably). Just saw the 3.42 on the dodge site, and thought it was cool. Have you gotten any reflashes? And no, there's not really a way to dodge (no pun intended) the warranty with the Spartan and DPF delete. Good luck.
 
#11 ·
OK... YOU HAVE AN 8000LB TRUCK WITH THE AERODYNAMICS OF A BRICK... YOU CANNOT EXPECT TO GET GOOD MILAGE OUT OF THIS TRUCK... I AM SICK OF READING ABOUT HORRIBLE MILAGE. YOU SHOULD OF RESEARCHED MORE PRIOR TO PURCHASING YOUR TRUCK AND MAYBE YOU SHOULD OF GONE WITH A HONDA OR A HYUNDAI...I WISH THE MODERATORS WOULD DELETE ALL THESE DAMN POSTS CRYING ABOUT FUEL MILAGE, THEY ARE POINTLESS... IF YOU CANT AFFORD A TRUCK YOU SHOULD OF GOTTEN A CAR... OTHERWISE DONT B!TCH!
 
#12 · (Edited)
I agree but damn, your mean lol

I've graduated from 10.4MPG to 13.5!!! God I hate winter blend.
 
#14 ·
well its gettign rediculous everytime i get on this forum or any other diesel forum there is someone new b!tching about their milage. then they want help... do some research there is oodles of information. :bdh:

I couldnt even tell you what my truck gets as far as milage because it doesnt really matter, you buy a ford because its the toughest, strongest, best damn looking truck on the road if your worried about milage and need a truck go by a honda ridgeline.:doh:
 
#15 ·
6.4's aren't designed for fuel milage, they are designed for the EPA to get off their back. So MPG's are sacraficed. Now in my 7.3, I only get on average maybe 12MPG, then once the summer rolls around and I don't have to add a bunch of crap to the fuel, and running on regualr diesel blend, I can bust out an average between 19-21, the best tank I ever saw was 21.9 last year.
 
#19 ·
Now I have an OBS and I know that when I did an intake and exhaust my mileage went up. I'm not sure about the aftermarket for the 6.4, but you may try the simple bolt ons, maybe look into the hypertech econ programmer. From what I have read, that DPF thing has to go, let that thing breath. You may also try a little taller tire, you could pick up a little on the freeway.

Just for grins..... how about 13.7 mpg pulling a 36' 5th wheel, not bad in my book.
 
#22 ·
ALL of the 07.5-09 diesel trucks are getting bad fuel economy. Gotta love the EPA:hehe:. Lets save the enviroment by burning more natural resources. There is one thing for sure...:icon_ford:is having the least amount of problems.:thumb:
 
#24 ·
I thought the whole point of a forum is to ask and answer ?'s. thanks to anyone who replied with something helpful. I wasn't *****ing I was simply asking a ? as to if anyone has had the same problems as me and if anyone had any ideas on something, if anything that would help. 2008TTCC says that i should have done my research before i bought the truck maybe he should try reading the post before he opens his ****ing mouth. In my post i stated that i tow an 11,000lb trailer i don't think that a honda is going to do that very well thats why i bought the truck that i did. I was simply wondering if there was anything i could do to help the truck do the job more efficiently. if you don't know what mpg's you're getting then you must have more money than brains or no brains at all. If there wasn't so many jack@$$'s like that maybe diesel fuel wouldn't be more expsensive than gas. If you don't like a thread or have nothing to say that might help than just try keeping your f**king mouth shut.
 
#29 ·
gotta love it, thank you! sometimes it's just easier to ask a question yourself instead of searching for it. Sorry, I was just looking at your post for the heck of it, I don't know how to help you out. You didn't do nothin wrong, if someone has a problem they can easily keep their mouth shut. good luck with the better mileage man.
 
#27 ·
My 6.4 is stock and MY average driving keeps me around 15-15.5MPG. If I try hard (58mph down highway, slow starts from stop lights, etc) I can get better than 17mpg.

OP: I'd say there is something wrong, but unfortunately I don't know where to tell you to start.
 
#37 ·
My milage is the same as FiveFlat's on my stock F250 6.4L with 3.73's. I think it has a lot to do with how you drive it. I don't get into the pedal unless I need it to merge with traffic and stuff. I don't baby the truck either. Going down the highway at 65mph I always seem to get better than 18mpg. For my daily commuting 20 miles each way on two lane blacktop roads going around 60 I get right at 15. This is as good or better than my F150 (2002) V8 was getting.
 
#28 ·
Get yourself a Spartan tuner and tell them what you're goals are. They can leave the dpf in for you if that is what you wish and I'm sure they can increase your mileage.
Dave
 
#30 ·
I have read this thread and had to reply. For those guys who know diesels then disregaurd my reply. I'm tired of guys getting on here and saying deal with the mileage. Or buy a Honda. You are the ones who don't understand. The real reason for owning a diesl was for the power, longevity, AND ECONOMY!! Yes I realize the EPA have ruined it for us choking our trucks, but diesels need to be economical to run as well. As far as the research thing goes, When I bought mine, there wasn't much info on here about horrible mileage or radiator problems. So thank you EPA for ruining our mileage, and thank you city boy for making my diesel too quiet. Those guys that know what diesels are for will appreciate this.

-Funkster-
 
#31 ·
I agree:thumb: Most diesels are not happy unless they a working....that is what they were made for. And if someone wants better mileage...it is listed on the forums everywhere. But don't tow at 80(when your trailer tires are most likely rated for 65...I don't know about you, but I don't want to kill anyone) and expect 12-15 towing. Or don't expect 20 empty running 85. If you do not want to mod your truck for better economy...try the speed limit for starters.
 
#35 ·
I've got some new good news. last week i changed fuel filters and started running fords octane booster. so far city mpg has gone from the poor 9 i was at up to 13.4. I haven't ran at all on the highway but i figured i would post the big city mpg change. the octane booster is only $7 and it treats 125 gallons. I'm not sure if it's the booster or the filters that made the increase but i'm pretty happy with it and hope it stays up.
 
#36 ·
Good to hear:thumb:
 
#39 ·
Went out over easter weekend towed 200 mile's and got 9.1mpg's. not sure what it is but i'm still using the additive and everything seems to be good. the one thing that i have learned is everyone with these trucks is seeing different mpg's but i would say anything is worth a try.
 
#40 ·
I think 7.3l-2-6.4l was getting some stinky fuel. I've used a couple of bottles of Ford's cetane improver and not seen much difference.

Not good evidence with only a sample size of 1, but bought fuel at a big real truck stop on interstate and saw MPG jump. Was displaying 14 MPG on the way down, 18 to 20 on the way back the next day with the cheap truck stop fuel. Then again I know good and well I was driving into a headwind for 14 MPG and had still late afternoon early evening air for the 18 MPG. Measured at the next fill I saw 17 honest MPG average.
 
#42 ·
I have been filling up at the same station before and after the increase. I don't think that i had a bad batch for thousands of miles then in luck saw an increase that just so happened to be when i started using the booster and changed my filters. I'm not saying that it will work for everyone but it seems to be working for me. just the same as some are seeing great mpgs with 6 inch lifts and 37's and others are seeing horrible with stock tires and no lift. I'm going to run my next two tanks with out any booster to see if it's the booster or the filters that made the difference and i will post any change.
 
#43 ·
k so this hopefully will be my last post in the bad mpg's:woot:. i ran one one tank without the booster and got 11.6 better then what i was getting but still not as good as with the booster. I would definetley say give the booster a try. i've talk to a few more guys and some have had the same results as me but others have not. As for me mpg's should go way up finnally i got the wife to let me buy the spartan and delete :woot::icon_ford::woot: ordered it from cobbs two days ago and i'm like a kid before christmas waiting for it arrive.
 
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