My untouched 7.3, meaning not chipped out, gets on straight #2 20mpg. With the winter blend I am looking at around the 17 mark on the highway. In town with the stop and go, then she drops down to the 12 mark.

 

For those doing 19's and 20's on a regular bassis you need to let Ford Know about that as they need to see what is different about your diesel we can't do that.
Now we did hit the reset on the MPG O meter while doing 70 MPH on the interstate..it ran up to over 27 MPG.(wish I could have got a picture of that) then it ran down to the usual 15's.I tried that a cpuple of times and it did the same thing...Sorry the very high readings are not typical and something else is effecting those readings.

 

Well, for one thing, I have 3.73s and a manual tranny.

Who should I contact at Ford?

D.

 

Believe the big secret is the manual with 3.73's. I know with my auto when I try to accelerate just a little taking off or going up the hill from our house you have to push down quite a bit and the boost goes above above 25. The auto is so heavy duty it takes up a lot of extra hp to get it moving and keep it moving. My 99 with the manual took a lot less effort. If fuel milage was my number 1 concern I would go with the manual again. Pulling our 5ver, my wife drives it too and the auto does better for us all around at this time. I do not understand why so many people doubt what this truck can do under ideal circumstances. manual with 3.73's a lighter truck and keeping it under 2000 rpms = better fuel milage. My 450 auto 4.30's heavier truck above 2,000 rpms = lower fuel milage. Also one other note, these trucks are so massive in the front they do not cut through the air as good as other vehicles at higher speeds.

 

I'm responding on my phone....didn't know we were in English Lit. class....like I said, "not to be a Jerk" .

 

they must have done something really special with these new motors....not!! my '05 cc, 3.73, manual trans. 6.0 never got better than 17 on the highway unloaded. that was driving like gramps too. i don't care what trans, diff etc. you have, these trucks are not going to get 22.5mpg. with all the emissions bs and weight of these trucks, it's just not going to happen. and for those of you saying you'll take a picture, what does that prove. first the lie-o-meters are called that for a reason. second, you must have reset them not long before snapping the pic. tell you what, don't reset the meter for 2 or 3 months. then driving wherever you want take a picture of it. if it says 22.5 i'll kiss your a$$. anyone can get the meter to read an erroneously high number by resetting the meter, driving down a 6% grade with a 30mph tail wind. not trying to rail on anyone. but i have a lot of buddies with diesels, from the 7.3 to the 6.4 and and other brands too. the best i see in real world driving is from the 7.3l and the cummins 5.9. those guys get 18-20 hwy. haven't seen any of the others come close. my new 6.7 averages 14-15 mixed.

 

You are right. I am either wrong or lying.

 

Well I was traveling from Beckley, WV to Covington Va last Saturday on I-64. Went down Sandstone Mountain (about 5 miles, 7% grade), when I got to the bottom my MPG showed 25.6! Of course when I leveled out it settled in around 13.5 again. On the way back home later that evening I had to go back up that same mountain. When I got to the top my MPG showed 9.7! The only way we're ever going to see GOOD mpg's is to get rid of all that junk in the exhaust.

 

Well I don't know what they did to my truck but here is the story. Took it in to the local Ford dealer for the routine 6K (heavy towing) maint, Oil Filter, Etc. I had in hand the list of TSB's and Broadcast bulletins that I copied of this site and asked them if they would check everything out to see if my truck was up to standards as I was concerned if the MPG is as good as it could be, They checked their Computer against my list and separated the TSB's from the bulletin. Meanwhile John..the diesel guy said..lets go for a ride and we did . He performed the dreaded Boost test where they try to jerk the turbo out though the front of the truck..we did it twice.It howled and screamed and I hope I never see those RPM numbers again on my motor but the diesel guy said...you got a good motor.

We now have 6600 miles on the truck and we are getting a good 1.5/2MPg better MPG. I ran it 600 miles, same fuel, same roads , same speed.There is nothing on my work order/bill other than the maint $93.38. I do use Power service diesel Kleen but I have for long time and we run 70psi in all the tires.Example we ran over 55 miles today
mixed driving but most at 35 to 55 miles per hour with several traffic signals and some under 35 stop and go traffic.. the MPG O meter said 16.2 when we got home and that is about average over the last 600 miles..That is nearly 2MPG better than before we took it in for service.. what did they do or has a miracle occurred.??????

 

these 60 and 100 mile trips people are averaging are not near enough. with small differences in the actual amount of fuel pumped in each time, driving conditions, terrain etc., the only way to even closely compute mpg's is to run say 6 full tanks, average each one BY HAND, then average the 6 averages. don't even look at the meter during those 6 tanks. then post on here how accurate your lie-o-meters are.

 

Hey Dave, Do you live in Staunton or Glouchester? I have a blue 08 XLT with the manual same setup, supercab is the cab with suicide doors btw. And Ive got just over 3000 mi on mine and have never seen over 16.4 handcalculated and yep its not much off of the computer, and thats babying the gears and pedal. Which can be a hard thing to do on it. hehe I live in staunton and yet havent made a trip like that but still doesnt seem right, everyone I know that has a 08 hasnt really been able to do over 15 most of the time, and yes the manual seems to be the trick so far... once the warranty is gone though, by by DPF

I'll be making a trip to Lynchburg here in the next couple weeks and we'll see..

 

Well, I'll tell ya. I think a person might be able to get 20mph but there are so many factors that will reduce that number, most people won't see it.

All these will knock down your mpg:

1) Driving over 65mph (or 1800rpm)
2) Wet roads
3) Headwinds
4) Cold weather
5) Winter blend diesel (see number 4)
6) Tire pressure
7) Hilly terain
8) Lead foot
9) regen

And more, I'm sure, that I have missed. Any one of these will knock 1-2mpg off your total. Combine a couple and, well, there ya go.

 

#'s 2,3,4,5,7,9 are all out of our control. we deal with those and more factors every day. you are correct. anyone can see 20+ for a short duration under the right circumstances. but, 20+ is just not going to be the average over a longer (more realistic) time frame.

 

the averages were taken over 600 miles Service at 6K and now at 6.6K. I let 600 miles go by before I was convinced of better MPG.I have hand calculated several times.. fill up to the brim..run out 1/2 tank of fuel.. then fill to the brim again. The difference between hand calculating and the MPG O meter is .7 average with the advantage to hand calculating. We are defiantly getting better MPG and I am not sure what to attribute it to. I do hope this is a trend although I am not unhappy with te MPG on this large heavy truck.

 

that still only puts you at 15.5mpg when taking into account the .7 higher reading from the meter, and the stated 16.2mpg that you are getting. that is a totally believable #, and nothing like the 20+ that some are stating. i still think 600 miles is too few to get a really accurate average. i was saying more like 2000-3000 and averaging the average of each tank. but the 15-16 is right in the neighborhood that i get too. i just can't put any stock in these 20+ numbers. maybe i'll have to check my mileage after i reset my meter and head to the corner store. it's only about .75 miles away and all downhill. i'll have to wait for a good north(tail)wind though. then i'll take a pic of my 26.957214205 mpg!! who'd have ever guessed an 8000lb vehicle could do so well?!