Huge difference. On the 6.4 trucks, if they are running right and the DPF is functioning correctly, you should have no soot in the exhaust tips (correct me if I'm wrong 6.4 crowd). What you have to understand is that this reduction in emissions comes at a price (usually fuel mileage). Compounding the MPG problem with the 6.4 is that the computer injects diesel fuel into the DPF to burn off the particulate matter that accumulates inside it. Burning this extra fuel to clean the DPF is taking away from the mileage. It's fuel that's not being burned in the combustion chambers and thus not being used to motivate the truck.

Typically, the 7.3 gets better mileage than the 6.0 and the 6.0 tends to get better mileage than the 6.4. Each time Ford / Navistar came out with a new engine (7.3 to 6.0 to 6.4), the emissions standards were increasingly stringent. Each time you choke these engines down with emissions equipment, you tend to suffer in the mileage department.

Right now, I average 15-17 MPG in mixed driving. Best I've ever done was 21.7 on a long run. My sweet spot is around 68 MPH which puts me around 1900 RPM. I also run Diesel Kleen in every tank. I also tend to agree with the notion that the ULSD has something to do with the mileage.

 

since I first bought my 2007 F250 with the 6.0 I was woundering how many miles it is suppose to get. I always heard about these 20 plus trucks, but mine bone stock is around 14-16 and the interstate dont help much. My truck has the automatic trans and I thank that has something to do with it. I always wondered if any of that banks stuff would help enough to make it werth haveing. I do alot of towing and while towing it usealy goes down to 10 to 12 so if it would help to add on enough to be werth it then I would be ready to buy.

 

I run DK in every tank too. I'm sure that the ULSD limits the 7.3's performance since it was designed around LSD. Not to mention the fact that the ULSD doesn't help my o-rings at all either...

 

hey guys.
i've got a 05 250 sc 4x4 that's getting 14 hiway!! i've got a shell on the bed, but the rest is stock. what's up with that? i'm pretty tame on the pedal and brake. i drive 10 miles to and from work, 300 miles a week, and blow thru a tank in that time. it's awful. any thoughts on how to boost the mpg?
thanks

 

All of the new diesels have taken a hit in mileage due the the DPF and regen cycles. Ford seems to have taken the biggest hit because of increased regeneration cycles. I don't know if they are 100% cleaner or not, but they are definately in the 90's percentile for clean burning. Eventually the manufacturers will figure out how to make a clean burning diesel that makes power and delivers good fuel economy just like they did with gas engines of the 70's. They'll have to if they want to sell them. The question is, how much will it cost in terms of purchase price and maintenance expense?

 

Well, all I can say is
that if somebody came out with one of those
nifty side plates that sits
on the rear of the front quarter panels
on the newer trucks,
but which stated approximately

7.3
and proud of it.

 

That's one slow truck.

 

i get 20mpg on the highway at about 65mph. i have a weld in muffler, air raid intake and i run amsoil. before i switched to amsoil i was getting 17-18 mpg.

 

Keep in mind, that a new engine will get less MPG's than one with some miles on it too.

 

my 06 F250 6.0 only gets an avg of 15 around town and if I'm towing it drops to 11. I just did a run from Md to OH and back It avg 11 towing a 3 horse gooseneck with LQ. I had a 5.4 same truck but it didn't get any bettter mileage than the diesel I have now...

 

===========================================


!DOH!
Boy do I have THAT comin'.
thanks,
I'm a better man for it!!!

 

Yes the mpg on the newer trucks sounds very sad. Im going on word of mouth on that but i wont buy a new one with that low of mpg. On my 02 i get an avg of 18.2 with mixed driving. I can just get 20-20.5 on a long freeway trip with just light load in the bed. Id be scared to measure the mpg on a tank of city driving. I can allmost see the gauge move! Its probably 14. Now my Dads 06 got a measured 22 on a long highway trip empty, when it was new.
I suspect the low sulfer fuel is at fault but i cant prove it. I might have a very small drop on my truck with the newer fuel but its not much, if at all.
Alot of factors in mpg for sure. The new trucks sure look good. Maybe the weight and wind resistence are a problem too?

 

i talked to the service guy here and he said that the 6.0 is the worst for mpg and that the 7.3 is great. no competition.

 

Sorry - I couldn't resist. Nice truck BTW!

 

It's the emmissions stuff that's killing fuel mileage. I've read on other forums that elimination of the DPF and reprogramming to eliminate regeneration on the 6.4L trucks is good for an additional 4 mpg. Same for Dodge and Chevy. The tree huggers and EPA have killed the diesel fuel economy for now.