I just drove round trip from san diego to san felipe,baja california, Mexico total miles 650 round trip with some city driving while there vacationing with the family I got 13.2 mpg diving in to san felipe but coming back there was a lot of wind and i only got 10.5 mpg 2008 F250 6.4 power stroke 4x4 crewcab lwb pulling a total of 2500 pond trailer in it.
I must add that it was very very very windy and that played a big roll m speed was about 80 mph cruise controle most of the time wth towhaul mode off because it is light trailer.
this friday I will be pulling my fifth wheel toy hauler for the first time 15k pound total from san diego to hidden shores, AZ total trip 450 mile and i will post mpg when I come back.

 

2008 F450 w/4:88

75% city 25%highway. 312 miles, 32.5 gallons. 9.6mpg. (all unloaded)

90% City 255 miles, 29.8 gallons for 8.56 mpg. all unloaded again, was in regen for quite some time cause of the short trips I guess. I'm sure that was part of the decline this time.

 

75% City 25% HWY don't remember the miles but it was 10.3 MPG

 

My 96 7,3L PSD empty gets 18 MPG highway with chip set to performance.
Drop my fiver on and I get 12 MPG.
Shes got 170K on her.

I have been thinking about a 6.4 gues I'll wait a while

 

I had a 99 7.3 PSD with 122k on it, GREAT truck, just not enough of one for future plans.........15.5 avg running empty. 10-12 with the 5er on the back.

With about 2k on my F450 I'm at about an 11mpg avg, already have seen 13.4 on the lie-o-meter till I desided to run it at 83mph for about 10 miles......quickly back to 11.4, again on the lie-o-meter.

Throughly expect my 08 F450 to be 13-14 max empty and the same as my 99 towing. Obviously traffic and driving habits will conditions dictate all of the above.

 

there is a 3701 miles break in period.. hopefully you have less than that and it should improve..

 

Thanks for the post. I believe there are too many variables and driving styles for other peoples MPG to translate into what I might get. By comparing your new truck to your old one that takes out most of the variables (except for the lead foot with the new truck feeling)

 

Bigger factor then most will give credence to.

 

Just got back from a 1,100-mile trip to the Grand Canyon from San Diego (950 miles towing). Overall, I got 9.7 MPG doing an average of 60 MPH on the interstates. Total rig weighs in at just over 19,000 lbs (CAT Scale). Elevation started out around 500 ft. here in my area of San Diego to just over 4,000 ft at the Cajon Summit near Victorville, CA and back down to 400 ft at the Colorado River in Needles and then to ~6,000 ft in Williams, AZ to ~7,000 ft at the Grand Canyon, south rim. Best tank was 10.3 MPG and that included 130 empty miles at 70 MPH from Williams, AZ to the Grand Canyon Village.

(Side bar - The Grand Canyon Railway is a cool way to get to the National Park, but their RV Park, while convenient, is new and VERY Spartan visually, read no trees, just little sticks in the ground.)

Cruise control is great, set it at 60 MPH and it handled the grades with no problem, keeping me at 60 MPH uphill and down, even on 6% grades. Truckers probably hated me in AZ since I kept it at 60. I was going for mileage, not time. Pulled this huge grade climbing into Kingman, AZ and the temp gauges barely moved, both engine and transmission. Boost hit pretty close to 40 PSI.

I've had no problems with my truck and I love it. She's got just over 3,000 miles on her for my two months of ownership.

drisschoufa, I don't see how you got 13 MPG doing 80 and towing 2,500 lbs. you must have the 3.73 rear-end or something. What are the specs on your rig? You can see mine in my signature.

 

Great post Mattebury........Very useful information! Sounds like your truck is everything you'd hoped. Just wait till it's broke in

 

I agree that a few thousand miles of break-in should improve the mileage a good deal. My week old F350 long bed 6.4 4x4 w/ 3.73 rear improves every day as I drive to work in it! I know that will come to an end eventually - but at 620 miles put on it so far, my average has climbed from 11.5 when it left the showroom (a basically meaningless number) to 14.4 on the car meter so far. This is all empty miles between 50 - 60 mph - pulling a few long hills, sitting in some traffic, and a couple of passes of other cars on 2 lane roads too.

I picked up my first tank of fuel on wednesday, and I compared the math to the trip mpg readout, and in my case the readout was actually 2/10ths low - the display read 13.4 but my math said 13.6.

My next tank should be in a couple of days or so and it'll be interesting to see how the math compares to the gauge, and that the actual average is. Can't wait for my first highway trip.

I plan a tool box and hard shell tonneau for the back. That'll be another interesting mpg tale. My last truck was a V10 2004 F250 w/ 4.30 rear - which got 14 pretty consistently until I put the cover on - and then it went DOWN to 12.5 and stuck there for 2 years. So those covers don't always seem to provide the big gas benefit.

 

drisschoufa, I don't see how you got 13 MPG doing 80 and towing 2,500 lbs. you must have the 3.73 rear-end or something. What are the specs on your rig? You can see mine in my signature.[/QUOTE]

Yes I do 2008 F250 CREW CAB 4X4 LWB 3.73
I am leaving this morning to Hidden shores AZ I will let you know how I do I am pulling for the first time my 38 feet fifth wheel toy hauler 15000lbs I will post MPG when I come back.
On a another note I pulled the the 5th to camping world for sattelite install on wednsday and that was the first I pulled it with this new truck as when I purchased the 5er two weeks ago I did not have the hitch on my truck, well my truck did not sag in the back at all from the weight like it did when I pick it up using my friend 2007 F250 crew cab 4x4 lwb 3.73.
I went ahead and put airbags anyway just to be safe and to soften the ride also.

 

Wow, 3.73's pulling 15,000 lbs over the Cuyamaca Mountains will give your rig a workout, that's why I went with the 4.10's. You should really feel it when you come back climbing the grade out of the Imperial Valley. Good luck and let me know how it did.

 

Hi, new to the forum. 1000 miles on truck,getting 12.8 in city/highway average. I did notic that anything over 60 cuts off about 1.5 mpg. Guess I'll have to act my age and slow down


2008 f350 6.4 swb 4x4 4.10 rear end

 

4000 miles on my ccsb w/3.73 gears. I like my 08 a little more everyday. mpg is s l o w l y improving. I'm getting 9.75 mpg in town on trailer, 12 highway no trailer 65-75 mph, and 7-8 pulling 6000 pound wells cargo hinghway at 70-80 mph. On grades it sucks down to .08 to 3.6. Just went on a 270 mile trip with the trailer and it cost 120 bucks. Fuel just hit $3 in Utah.