6.4L Power Stroke Engine and DrivetrainDiscussion of the 6.4L Power Stroke diesel engine and drivetrain in the 2008 Super-Duty trucks. No gas engine discussion allowed except on transmissions and drivetrain that pertain to all models. Please confine discussion of topics in this forum to those items that are specific to the 6.4L Power Stroke engine.
I think I am being honest about my mileage but with miles at 5K I get little over 13 back and forth to work with the factory oil still in it. If I am just going down the highway at 55-60 it does get well over 20mpg and averages about 19. It does like to run 70-75 but the mileage really drops.
My 08 is still brand new - under 1,000 miles, but in mixed city/hwy driving (mostly hwy), I'm seeing about 14 mpg, which under the same conditions is about 2 mpg less then what my 05 with the 6.0 got. I drove my 6.0 harder though, I've taken it really easy on this. I'm hoping to pick up a couple mpg after 10 or 15K miles - my 6.0 really increased mpg after 15K miles on the clock.
Mines a 09/08 build F250 with 8300 miles. Running 60MPH empty I'm showing 20-22 MPG on the meter after zeroing it out. Gets far better highway mileage than my 2002 F250 with the 7.3 (which I still have and love) but the 2002 does excell in city/town mileage getting 16-17MPG.
My truck is stock with a little over 5000 miles and gets 14 mpg mixed driving. Interstate driving is getting 16 mpg. Pulling my 6000 lb trailer, I was getting 10 - 11 mpg. I have a job 3 with a 3.55 diff.
__________________
'08 F250 Lariat, 6.4L, Auto, 4x4, CC, Short Bed
Edge Insight & Air Lift Super Duty Air Springs
Normal driving & pulling a travel trailer
Last edited by CM71 : 06-22-2008 at 08:55 AM.
Reason: More info
Trip in Jan OKC to Galveston and back; just 3 people and lots of luggage, no towing: 12.47 mpg at 70 MPH
Round trip couple of weeks ago, solo, OKC to Grapevine, Irving, TX area; drove no faster than 60 MPH. Dash was indicating 16.4 MPG when I went to fill up; actual was 14.67 MPG for the 475.6 mile trip which included about 36 miles of city driving in TX. The dash was indicating 17.9 MPG when I first entered the DFW area then it started dropping to 17 IIRC as it went into regen. It was at 15.1 indicated MPG when we started trip home. I was very surprised that the indicated MPG was so far off from the actual MPG when I filled it up; and I was disappointed to say the least.
Just returned home from trip to Tenkiller Lake in Eastern Oklahoma pulling fifth wheel just shy of 14,000 lbs. The trip to the lake had about additional 40 miles since we pulled 5th from storage to home and returned it to storage on return trip from lake.
Plan was to keep it at 60 MPH on trip to the lake. This resulted in it downshifting on every little hill; ended up keeping it between 60-65 MPH. Cruise set to about 63 MPH, this puts me a little over 2000 RPM. Most hills it would pull w/o downshifting; some I would disengage cruise and slow down to 60 (or less) but w/o downshifting.
MPG ended up at 9.63 MPG.
Trip home (which was actually 40 fewer miles of towing the fifth wheel and also 308 miles vs. 353 on first tank) resulted in 8.21 MPG running at 70 MPH w/ cruise; only downshifted on a few steep grades.
Both fill-ups were with less than 15 miles to empty per the dash; both included about the same type of running around with respect to the non-towing miles. The non interstate driving was at posted speed limits when possible. Both trips include about 15 miles of narrow winding road with steep grades around the lake. Fill-ups were to the brim and generally my dash indicated MPG is .6-.8 optomistic with reality. I have reported hand calculated MPG here unless otherwise indicated. I reset the MPG every fill-up.
My 06 made the same trip in NOV 07 and I got 11.49 and 11.65 MPG respectively. I was running 65-70 MPH but the water tank was empty since I was pushing the GVWR of that truck. The GVWR on the fifth is 16,000 but we don't have it loaded to that point; and we have weighed it on the scales.
The 08 pulls much better and does better on the hills holding speed. I have other trips pulling the fiver and they are typically between 8.5-9.0 mpg so far.
The truck currently has 18,604 miles and 557 engine hours.
Bob
__________________
08 F350 DRW 4x4 Lariat CC 6.4 torqshift wide track front axle 4.10LS
07 Montego Bay 34RLB3 5th wheel
(traded the 04 w/ 56K mi. on 3/25/06; the 06 w/ 45K on 10/1/07)
I was very surprised that the indicated MPG was so far off from the actual MPG when I filled it up; and I was disappointed to say the least.
Unless you put in exactly the same amount of fuel as when you started, you will always be off from the dash computer. I know people say that their hand calculations are more accurate, but unless you have a visible calibration line set on your fuel tank to prove that you always start with the same amount of fuel, I'd expect my numbers to be different from what I pumped into the tank and what the dash computer is telling me. On a 300 mile trip, with the dash indicating 10 MPG which should be 30 gallons, a one gallon difference in what you actually pump into the tank and your hand calculated mileage could be as high as 10.3 (pumping 29 gallons) and as low as 9.7 (pumping 31 gallons).
Since the tank is opaque, it's impossible to tell after you fill-up, you have exactly the same amount of fuel as your last fill.
__________________
2008 6.4L F350 King Ranch, Crew Cab, Long Box, 4X4, Dual Rear Wheels, 4.10 rear-end
Trip in Jan OKC to Galveston and back; just 3 people and lots of luggage, no towing: 12.47 mpg at 70 MPH
Round trip couple of weeks ago, solo, OKC to Grapevine, Irving, TX area; drove no faster than 60 MPH. Dash was indicating 16.4 MPG when I went to fill up; actual was 14.67 MPG for the 475.6 mile trip which included about 36 miles of city driving in TX. The dash was indicating 17.9 MPG when I first entered the DFW area then it started dropping to 17 IIRC as it went into regen. It was at 15.1 indicated MPG when we started trip home. I was very surprised that the indicated MPG was so far off from the actual MPG when I filled it up; and I was disappointed to say the least.
Just returned home from trip to Tenkiller Lake in Eastern Oklahoma pulling fifth wheel just shy of 14,000 lbs. The trip to the lake had about additional 40 miles since we pulled 5th from storage to home and returned it to storage on return trip from lake.
Plan was to keep it at 60 MPH on trip to the lake. This resulted in it downshifting on every little hill; ended up keeping it between 60-65 MPH. Cruise set to about 63 MPH, this puts me a little over 2000 RPM. Most hills it would pull w/o downshifting; some I would disengage cruise and slow down to 60 (or less) but w/o downshifting.
MPG ended up at 9.63 MPG.
Trip home (which was actually 40 fewer miles of towing the fifth wheel and also 308 miles vs. 353 on first tank) resulted in 8.21 MPG running at 70 MPH w/ cruise; only downshifted on a few steep grades.
Both fill-ups were with less than 15 miles to empty per the dash; both included about the same type of running around with respect to the non-towing miles. The non interstate driving was at posted speed limits when possible. Both trips include about 15 miles of narrow winding road with steep grades around the lake. Fill-ups were to the brim and generally my dash indicated MPG is .6-.8 optomistic with reality. I have reported hand calculated MPG here unless otherwise indicated. I reset the MPG every fill-up.
My 06 made the same trip in NOV 07 and I got 11.49 and 11.65 MPG respectively. I was running 65-70 MPH but the water tank was empty since I was pushing the GVWR of that truck. The GVWR on the fifth is 16,000 but we don't have it loaded to that point; and we have weighed it on the scales.
The 08 pulls much better and does better on the hills holding speed. I have other trips pulling the fiver and they are typically between 8.5-9.0 mpg so far.
The truck currently has 18,604 miles and 557 engine hours.
Bob
this consistant with my truck....pulling either a 38 ' toyhauler (14,500# per the cat scale) or my carhauler I get between 7.5-9 and running empty on the highway (70-75 mph speed limit) 10.5-12.5 mpg all hand calculated as accurate as i can be.
pulls great and is the quietest diesel truck ive owned (02 f-350, 04.5 ram)
I currently have 20k miles on it ....
Love the truck but both of my prior diesels got better mileage. if you can overlook it then buy 1....its a great truck
Unless you put in exactly the same amount of fuel as when you started, you will always be off from the dash computer. I know people say that their hand calculations are more accurate, but unless you have a visible calibration line set on your fuel tank to prove that you always start with the same amount of fuel, I'd expect my numbers to be different from what I pumped into the tank and what the dash computer is telling me. On a 300 mile trip, with the dash indicating 10 MPG which should be 30 gallons, a one gallon difference in what you actually pump into the tank and your hand calculated mileage could be as high as 10.3 (pumping 29 gallons) and as low as 9.7 (pumping 31 gallons).
Since the tank is opaque, it's impossible to tell after you fill-up, you have exactly the same amount of fuel as your last fill.
as indicated in my post: "fillups were to the brim" I have been doing this since 1995 with my diesel trucks.
Liquid fuel about 1 inch below the filler cap opening; with a wait to insure no more air coming up with resulting settling. Same pump at the same fuel station too.
Maybe I bought fuel after a 'hot' unload at the beginning of the trip.
I have records comparing dash display to the actual MPG all the way back to the 04 and 06 trucks and have never had it that far off and I use to buy fuel at a station accussed by a big rig trucking magazine of selling 'hot' fuel.
Hot fuel is unlikely.... Not likely someone stole any either or why not take more? Subseqent tanks are back to fairly close so not likely I have an injector leaking either.
The difference is more than a gallon; even if assuming the display was .6 MPG too high and knocking it down from 16.4 to 15.8; 475.6 mi/15.8mpg = 30.101 gal; or 2.319 gallons less than I purchased.
Maybe I reset the thing and didn't realize it; or remember since that (my memory) seems to be going with age
Bob
__________________
08 F350 DRW 4x4 Lariat CC 6.4 torqshift wide track front axle 4.10LS
07 Montego Bay 34RLB3 5th wheel
(traded the 04 w/ 56K mi. on 3/25/06; the 06 w/ 45K on 10/1/07)
Towing anything=8mpg, regular driving mixed unloaded =10.5, I could be doing 60 or 80 doesn't matter. When I complained to the dealer he said that is what everyone is getting and there isn't anything he can do. That sucks. If anyone knows of a programmer that can give me 4-5mpg I will buy it and void the warranty. At 10mpg and ~28gal of fuel I can barely get anywhere.
I just sold my 99 and picked up my new (well new to me) 08 in Ft Worth last weekend. Had a 600 mile drive home to check out the mileage. It got a hand calculated 14.5 MPG running 70-75 most of the way home. Not stellar, but could have been worse i guess. I am interested to see how it does around town. The truck is great though, had a hard time parting with my old 99, but after a few hundred miles in the new one I wonder why I didnt do it sooner.
__________________ SOLD
-late 99 f-250 ext. cab shortbed 4x4.
-EGT/boost guages
-Pro-comp 4" lift, dual front shocks
-weld super-singles w/ 35/12.50 bfg A/Ts
-banks exhaust and downpipe
-zoodad mod
-'05 frontend.
-ATS housing
-gos racing headlight harness, silverstars
-DP Tuner
-4R100 HD
Just took a trip up north pulling my trailer (about 9K pounds) and I was able to squeeze almost 12 mpg out of the truck. I kept it at 65 mph for most of the trip. It's about 100 mi one way with a steep mountain pass in the midst of the trip. That's about the best I've gotten towing.
When not towing, I'm seeing about 14 mpg around town and 16-17 mpg on the highway.
__________________
2008 F250 CC SB 4x4 6.4L
2003 F250 CC SB 4x4 6.8L - SOLD
1994 F150 SC SB 4x4 5.0L - SOLD
I just drove mine from Virginia Beach VA to Sumas WA (~3100 miles), drove with the cruise control, didn't speed. Lots of it was 75mph, other times 65 or even 55mph. Truck has the performance tune loaded from the Superchips Flashpaq. I averaged about 12.5mpg for the total trip. 12mpg was pretty consistent while running at 75mph and 13-14 at 65 or slower.
To be quite honest, these numbers are not impressive to me at all after owning a 20+mpg (25mpg a couple times, honestly) duramax, but I'm surprised that I'm not doing any worse than the stock trucks seem to be doing, with this big lift and tires.
Here's what I would like to know. Why does my 7,000lb empty pickup truck not get much better fuel mileage than my 40,000lb empty 625hp 8-axle 30 tire square-box style completely unaerodynamic Peterbilt pulling two empty flat deck trailers?
I honestly wonder if the manufacturers are not purposely designing these trucks to be much harder on fuel than they could be. Fuel companies getting their fingers involved or what, I don't know, but things just don't seem to add up.
__________________
2008 F350 crew cab SRW LB 4x4 King Ranch, 40s on 22s, 10" Fabtech lift, big fat and slow
2005 F150 reg cab LB 4x4 XLT, 5.4 auto, 33s on 17s, 2" lift, FOR SALE
. It was at 15.1 indicated MPG when we started trip home. I was very surprised that the indicated MPG was so far off from the actual MPG when I filled it up; and I was disappointed to say the least.
Linear Mode
