I am happy with mine. Runs as well as or better than the 05 and is getting about the same mpg as when the 05 started out. The auto is working fine and the EB is better than the Pacbrake that I had. The 05 didn't get it's best fuel milage until it passed 20k so I think that I have a way to go before I can mumble if necessary.

 

Ouch... That hurts...

 

It would be useful when people complain about their fuel mileage, if they provided additional detail of their setup.

I have a new 2500 QC/SB 6.7 auto (600 miles) that is bone stock. It's a 4x4 w/3.73 gears and I have the stock Michelin tires running at 50 psi. I also have a tonneau cover. Around town in stop & go and 2 lane 50 mph driving, I get 14.7 mpg hand calculated. On the interstate with the cruise on at 75 mph I get 16-17. Not bad for a big heavy 4x4 that can easily tow 12K and thats not broke in yet.

When people start putting 6" lift kits on they increase the aero drag by letting more air in under the truck. They add bigger tires that increases the gear ratio and actually increases aero drag. They add winch bumpers and service beds and other stuff adding a lot of weight. They drive around town trying to drag race every GT Mustand in sight. I can understand why the fuel mileage numbers will go down under those conditions.

 

Well. You guys have pointed out the obvious, but we're talking about 4x4 5.9s w/ 35" tires and all the other crap hanging off of them, that truely do get in the 20mpg range. Hell, my Dad gets 25-26mpg w/ 07 2wd 6spd 5.9L stock. You guys w/ 6.7L will never see that, even w/ little bitty 265/70/17s and no mods or even modded for that matter. That is the comparison issue at hand and the reason so many want a 5.9L. Basically the 6.7L was designed to meet EPA rules/regulations, it's already been shown that they don't put much if any more power to the rear wheels than a 5.9L. I wonder how much HP and MPG is robbed trying to suck/push air through and around EGRs and DPFs.
Have you read the manual and the warning fliers(hanging in the cab) regarding changing your driving style so that the DPF can regenerate, for as long as 45mins? That's nuts! I only change my driving style to repair my blown up tranny or because I'm running out of diesel!

 

I drive my 6.7 dually like I stole it! I had the 5.9 and would not go back, the tranny alone is not worth going back unless you go manual and even then I would stick with my 6.7 6 speed auto. It's just a matter of time before this is all straightened out with the dpf. I really liked my 5.9 until I got the 6.7, my truck works, tows, and really gets driven and I have 4K miles in 4 weeks with no issues yet. I hope I didn't jinx myself!!! Good luck with your 5.9, either way they are both great trucks and I'm sure you can have more fun with all the mod's you can do, I sure miss that.

 

Bonham and Greenville TX had a bunch of 07 5.9 and they did me pretty good deal. I can tell with just right 400 miles on my new truck I am aready getting better fuel mileage compare to my 6.7. On my 6.7 I would be right at empty. I had love the way the 6.7 drive but I did not like the fuel mileage. I had even slow down my driving and setting my cruise at 65 and I did all highway miles pretty much and I would just get 410 miles out of it. Maybe they will get better in the next couple of years.

 

I too will be getting another 5.9 this sat.
My 6.7 caught some grass on fire yesterday and that pretty much did it for me.
I cant see myself trying to explain it to my Dad that I caught the pasture on fire and all his longhorns where killed.My last tank of fuel I only got 325 miles.
My 05 sb qc 4x4 on 35's with a 5 inch lift still went 450-475 miles on a single tank.
The short time I have had my 6.7 It has been awesome, the power is great and the transmission is even better but I really do miss that sweat sound of a 24 valve strait piped, and seein a little black smoke..
Those of you with the 6.7's MAY THE FORCE BE WITH YOU..
New truck is a 2500 sb qc 4x4 with a 6 speed. My test box ( JUICE ) Is going back to Edge and they are sending me another for my 5.9 at no extra cost, that just goes to show you how good of folks they really are at Edge..

 

Ahh!!! now I know what you are talking about! Thanks for clearing that up Fatcat.

 

I wondered how long it would be before reports of pasture/field fires started coming in. These new exhaust systems are dangerous!

 

I think the edge may have caused your fire honestly. My dads got the 6.7 and my buddy has one as well. My buddy is a farmer and he lets that sucker idle all day with the air on. Also had the enclosed hooked to his truck for 450 miles and no signs of heat.

 

Greed is good...greed is right...

 

the edge didn't cause the fire because the edge does not make the truck go into regen. The truck tells it go into regen it not like the bully dog were you can put in like a manually mode.

 

I thought phil was on here too when he was having issues with his rig saying he was gonna get a 6.7. now you traded yours and he still has his. the emissions crap is not all its cracked up to be. I think you made the right choice going back with the 5.9. you can be happy in the aftermarket world again

 

I can understand your frustration and why you traded. About 3 months ago I was all ready to buy a 6.7 but I got scared by the complaints starting to pop up. As soon as someone offers a proven kit to remove the dpf and egr I will buy a 6.7, off-road use only of course.

 

Really?

My fuel mileage topped out somewhere betweeen 7500 & 10k miles.

You could probably measure the difference in mpg at 10k and 20k miles, if there is one at all, in grams of fuel.

By XMAS time we should all have a good idea of how well the 6.7 does in the mpg category.

My bet is it will disappoint.

DT.