6.7L mpg

[RRuggles]

I now have 10,000 miles on my 2008. Unloaded highway mileage has increased from 15 mpg to 18 mpg. Towing my travel trailer shows a low of 11. 2 mpg with strong headwinds to 13. 6 mpg with good towing conditions. Somewhere in the 12 mpg range is the most typical. I got the same towing mileage with my 2001 but it got 2 to 5 mpg more unloaded highway driving. I love the power and the new 6 speed automatic. I very rarely use the tow/haul. Guess I might in the mountains. Another plus is that my wife likes to drive this truck but would not drive the 2001 with its sloppy steering.

 

[jelag]

I've got a 5500 running very close to your loaded mileage at around 10-10. 5 with 19,500 lbs..... the truck now has 9,000 miles or so and runs very well... . and out performs the F550 we are taking out of service.....

The only draw back is that we don't have good enough springs on the rear... PacBrake is putting together an air bag kit for me... . hopefully it will be ready soon... . We're going to install a self leveling valve like what we have on the air bag suspension of our larger trucks.....

We like the automatic and the way it runs.....

 

[klenger]

I think that's one of the best 6. 7L reports I've heard yet. I hope yours continues to improve and I hope Dodge continues to improve them.



My current feeling is that for my next RV, I'm going to give up on the 5th wheel CTD thing and get a Winnebago Ford V10 Class A motor home. I've already picked one out, now I just need $100,000.

 

[obie1]

Less than 1500 miles and my mileage (primarily highway) went form 12 to presently at 17. Much better than what my 2006 MC 5. 9 did when new (it was 12 and didn't get 17 till after 15000 miles)

 

[Hounddog]

6.7 mpg

My 07. 5 was getting 15 hwy 10 towing, till I got the AX tune loaded at my 10k oil change. Took a 1300mi round trip from Abq, NM to Dodd City,TX to pick up my trailer, tractor, backhoe and other tools. On the way over (unloaded) we avg 17. 5mpg(calculated). On the return trip (loaded), had wood chipper in bed of truck and trailer with tractor, front loader, backhoe, box blade, post hole digger and rake behind, even into a headwind most of the return trip we, avg 11. 5 (calculated. Was very pleased. When we dropped the tractor off at our land and returned to Alb, we got 20. 9mpg with a tailwind and unloaded! I had heard the AX tuned helped mileage but I'm really happy with the results now.

 

[jersey diesel]

What is "AX tune"

TKS steve

 

[jimnance]

Latest PCM software update from Dodge.

 

[CPracht]

I just did a trip to Las Vegas from Southern California across the Mojave desert. A 240 mile trip one way. All the way I drove into a 50 mph headwind and at times going up hill through the Baker grade, a tough long incline. I locked the speed in at 70mph with the cruise control. I had 1200 miles on the truck at that time and I was amazed that I got 19. 2 MPG hand caculated when I got home and refueled. I would imagine if there was no head wind I would have had MPG's in the twenties and it is no where near being broke in yet! Amazing truck!!



Chris

 

[jtwcummins]

I also got great mileage on 1100 & 1500+ mile trips to So Calif and back. Used cruise at 70 and got 19. 4 going south and 18. 4 coming back average for both trips. Have just less than 6k miles. I have also found the overhead to be only a couple of tenths off hand calc mileage.



My big problem is without using cruise this truck wants to roll along 80-85 and gets there fast. 80 is about 2000 rpm. If fuel was cheaper I run faster!

 

[DSass]

No Engine Updates?

I just recently pulled my 5th whl to CA from WA and back. It weighs around 14500K and was really disappointed with the mpg. Going down, got 9. 2 at destination and 10. 2 mpg on the return. When I got to Ca I called the local dealer and he checked my VIN to see if it was in need of any updates, and he said it wasn't. Being a 08, he said it was built after the cut off and that his experience has been that 15K seems to be the magic number for increase in mpg with these new trucks. We'll see. I am now at 7K miles on the truck and hope that the mpg goes up. Unloaded it is now getting around 13. 5 mpg. I changed the oil at 5K and switched to 100% synthetic and had analysis done on the drained oil. All looks good, just normal break in contaminates, iron etc. Mostly all A's.



I love the 6spd auto with the exhaust brake. Makes you feel like you have control more than the others that I have towed with.

 

[grasmo]

My 04 duramax had a sudden jump in performance and the only thing I could figure was it had just hit 15k exactly. I wonder if it could be written into the programming to allow more timing / fuel at a predetermined time/mileage?????? Dodge ?????? Chevy??????

 

[JimLarsen]

With my 07. 5 with about 10,000 on it, I got only 15mpg on a round trip to Portland Or. I did have a light load both ways that stuck up above the bed sides. On a 400 mile trip from St George to SLC, Ut. I got 18. 4mpg. I was empty. This has been the highest of all my runs. In the next three weeks I hope to rack up some 5th wheel time. Hopefully now that I have 12,000 miles on the truck the mileage will grow. I am thinking of putting in an Edge chip and defeating some of the exhaust cleaning in order to get better mileage. Any one have any thought or horror stories I should hear befoe attempting this change?

 

[CUMMINZ]

jelag,



Please take a good clear photo of both ends of your rear springs while max loaded and email them to me.



Thanks

 

[JimLarsen]

The 10,000 I listed was miles on the truck, not the weight. Sorry, I need to go back to school and take a writting class

 

[teebarjake]

My dealer dosn't recognize any flash by AX Tune is their a service bulletin # as a reference?

 

[teebarjake]

help with flash code for better MPG

I have a 2007. 5 one ton single cab with 26,000 miles. Empty I sometimes get 13 mpg but with just a two horse alummin trayler im down to 10. 5 MPG. I know that my 2007 with the 5. 9 will pull this same trayler at 15. 5 MPG or more. We have also a large 4 hourse livingquarter trayler that weighs in at 20,000 LBS and the 5. 9 will get 12-13 mpg and this 6. 7 is 9. 5-10. 5. same haul about 120 miles with road speeds of between 50-60 MPH. Both are stock. I cant't keep this up?

 

[CUMMINZ]

Teebar,



My love goes out to you.



I will say this. Take your 5. 9 and load it with that 20k trailer. Park it on a steep incline and get it started up the hill. Do the same and back it up a steep incline into a campsite. Then do it with your 6. 7.



There is your differnece.





I will take the bad fuel milage anyday.



CumminZ

 

[catoiler]

I am having a hard time beliving the upper teens reports. best I have ever got was 14. it is always at 11. 5 around town. if someone around socal with one of these trucks wants to trade for a week that is about the only way I will believe it.

 

[catoiler]

Teebar,



My love goes out to you.



I will say this. Take your 5. 9 and load it with that 20k trailer. Park it on a steep incline and get it started up the hill. Do the same and back it up a steep incline into a campsite. Then do it with your 6. 7.



There is your differnece.





I will take the bad fuel milage anyday.



CumminZ

What are you sayin the 5. 9 won't do it? it will with no problem. his milage looks to be right on for both trucks.

 

[jimnance]

I haven't pulled a heavy load very far yet with my '07. 5. However, around town/highway driving seems to be 15-16 MPG if I take it easy. My '05 with an Edge Attitude on level 2 gets about the same mileage, but it's a dually.



When towing my 14. 5K fifth wheel with the '05 again on level 2, I figure 10 MPG +/- . 5 MPG. I expect the '07. 5 will be similar since the base mileage is comparable.



BTW, I have pulled a 30' long horse trailer up a grade with the new truck. Pulls about the same as the '05 on level 2.