Mine is 2WD and I average 11-12 empty. In my case shift on the fly is not an option. Not great but it is what it is.

 

honestly i am not sure. there are always updates and parameter changes being done so it is tough to keep up with the latest and greatest right now.

 

How do we get these new updates. Do we really want to get them if we are not having problems. I saw the link that had the dash showing when truck is in regen and thought that would be nice to know. BUT, what am I going to get when they put that flash on the truck? Will I create new problems that I did not have before? This seems that it could be a catch 22.

Tom

 

i havent heard of any associated issues with reflashing on a 6.4

 

What are people comparing the mpg figures to? If they're being compared to the previous emissions tier, that explains most of the problem. I've run turbo diesels since 2001 starting off with an excellent 7.3, moving to the 6.0 in 03', then a Cummins HO in 05' and finally a Duramax LBZ in 06'. I immediately noticed a 2+ mpg drop with the government mandated switch to "Ultra Low Sulfur Diesel". Same truck, different fuel, less efficient. The next hit was the 2007 tier in emmisions. I have buddies who drive the new Duramax and have spoken with 6.7 Cummins owners. The new "emissions tier" trucks, plain and simple, are not as efficient as the 2006-2007 and prior models.

If you consider a previous generation diesel got around 16+ mpg in all around driving with "good" fuel. (20+ mpg highway) The current mileage figures make complete sense. It isn't the manufacturers fault, IMO it is the Government and EPA who is to blame for the **** poor efficieny in the 2008+ diesels.

Just my 2 cents.

 

Coming from someone that actually noticed a decrease in performance, on the same truck, using ULSD, is pretty interesting. I had heard others say "It must be the ULSD". But actual experience is pretty convincing.
Haven't heard any mileage numbers on the 6.7 Would be interested in that though. Wonder how much the Dodge boys got hit in the MPG dept.?

 

I have heard the ford has the worst mileage out of the three. But, has great pulling power, best ride, nice interior, pretty solid and very reliable engine. Cummins has decent mileage but having BIG DPF problems. and The Isuzu...is an isuzu Booo

 

I have a job 2 w/ 14k miand manual hubs. I keep my tires at recommended 80 psi rear and 60 front. I get real sh---- mpg in and out of town. In town no trailer is 8-9, towing in town is 7-8. towing hwy is 8-9 at 75 (7k lb trailer enclosed) and no trailer hwy at 75 has NEVER been above 12. Oh yea I have a dpf delete too. Only improved towing mpg by about 1-2. Hope this helps.

 

What about the poor mileage on 4X2 trucks? There is no front axle to cause any drag there. My buddy has an 08 6.4L and he is constantly complaining to anyone who will listen at Ford dealer about the poor mileage. He took it in and they ran some test and determined everything was normal. Well my O5 6.0L gets solo 15 or better and tows 12,500# getting 9 and 10 mpg. I am glad I didn't run out and buy the new one though I was tempted to. Hopefully they will get this problem fixed if there is a fix!

 

I am the current owner of a 2008 F-350 with a 6.4L and it is a Crew cab with a short bed. I had the exact same truck with a 7.3 in 2001 even down to a 2.5" leveling kit and 35" BFG Mudders and since the Low USLD came out my mileage on my 2001 dropped 2 mpg all the way around. I was getting 9.5 to 10.5 all winter out of my 7.3 this last year and I am getting 10.5 to 12.0 with my 6.4 with the same route to work, same everything. I have to say I may be the only person on here happy with my trucks fuel mileage because it gets better than my other truck did!

 

I have a Job 3 F450 4x4 dually crew with auto and 4.30 gears. I just towed my 12K lb triple axle boat on the interstate at 65 mph and got 9 mpg. Around town and on the interestate empty at 65 mph it gets 13-13.5 mpg. All mileage is hand calculated in northern VA, not totally flat but no mountains.

Coming from a 2001 V10 4x4 auto with 3.73 gears, I am not terribly upset with the 6.4s mileage and it tows sooo much nicer than my old truck.

 

About identical milage, came from a 99 v10 Manual with 3.73s

 

Just got my F450..pulling he same 40' fifth wheel I get just a little better than my 2002 Duramax....6.5 - 7.0 mpg but it is so smooth and nice ..love it

 

I was listening to a “truckers radio station” last nite and some of the discussion was about the fuel mileage the new 2008 18 wheelers were getting. It seems that before the change in emissions and the USDL you could expect to see 6 and maybe as high as 7 MPG depending. Now with the new trucks (they have the DPF's also) and USDL it seems that many drivers are getting as low a 4.5 MPG and hoping for 5 to 5.5 MPG.

I think that the new emissions regs (DPF) and USDL are the big reasons for the drop in fuel mileage.

 

Their doesn't SEEM to be the spread with the duramax, BUT I have a cousin that claims great mileage, but when the 2 people switched trucks, the mileage was the SAME. Some people naturally exagerate, and some people are naturally hard on the throttle. I honestly don't think that there is a huge spread in fuel mileage like everyone claims pertaining to the actual truck. I think it has a lot to do with how the truck is driven and the particular route a person runs every given day by nature and location.

One person still lives at the top of a hill .1 of a mile from a stop sign and drives 5 more miles to town and has 3 more stop signs to get a cup of coffee at a local gas station while leaving the truck running. The other guy may live on a flat road and drive the same 5 miles on a straight road and turn the motor off when they go to get a cup of coffee. It all matters.

When the 2 guys switched with identical trucks, the mileage was identical. One person still got 3 mpg better than the other person, and the "great mileage truck" still got bad mileage with a different driver.

Warranty or no warranty, a tuner of some kind CAN and WILL help your mileage if you can find the right one for your driving style.