I traded my '03 2500HD Dmax/Allison 2WD on an '05 3500 dually Dmax/Allison. I tow a 48' enclosed car trailer, and it was a little crazy at times with a 3/4-ton short-bed truck. ;) I can immediately feel the weight difference between the two trucks. Stock-for-stock, the 3500 is just a pig. I didn't buy it for its svelt characteristics, but I was shocked at how much I could FEEL the difference. The dually also took a considerable hit on gas mileage, which I expected. On the highway unloaded with the '03, I would average 21-21.5 MPG doing 70 MPH. With the '05, I'm averaging 14.2-14.4 MPG at 70 MPH unloaded. It gets the same mileage whether driving in town or on the highway. The LLY has quite a bit more "rattle" to it driving down the road. It's still very quiet at idle, though. I ran the Edge Hot Juice w/ Attitude on my '03, along with a Magnaflow 4" cat-back and K&N FIPK, and I'm currently debating my choice on tuning for the '05. I've heard of quite a few problems with the Edge and the LLY, so I'm still deciding. I've got a Juice/Attitude on the shelf, so I may give it a try this week. :)

I would tow on level 1 with the '03, and the LB7 could handle the load without blinking an eye. With two cars in the trailer, we'd average 16,000-17,000 lb. loaded. I could knock down 10-10.5 MPG buzzing down the road at 70-75 MPH, so I'm curious as to where I'll be with the dually. I was honestly shocked at how well the LB7 pulled the load. It rarely ever downshifted. I have my fingers crossed that the LLY will do equally well. The '05 is currently bone-stock, but I'm anxious to hook the trailer up to it just to see how she fares. I need to give it a few more break-in miles, though. I know it will feel better from the suspension/wheelbase standpoint, but I really hope it has the power. I'll let everyone know how it does. :)

Trevor

I don't know of a whole bunch of problems with the Edge and the LLY.. only ones I can think of are when some run the Edge at its maximum and start breaking things and then there is the issues with the Edge and having old code on your EEC. Once people get the reflash the edge works great..personally just reinstalled mine and its fine.

You got a much heavier truck, but the LLY should have no problem pulling anything. You already have about 90ftlbs of more torque.

I have seen a common mileage thing though..where it is high when new, then goes down, but creeps back up with each tank. going through this myself.

Good luck with the new truck!!

a freind has bought a 3500 lly, traded the lb7 as well, mileage and power were his same concerns, got him a bullydog and now is on the 90,220tq setting, says it is close to his last one, if intrested i have another one to get rid of, thanks fred

That kind of MPG seems normal for the 3500 ours gets roughly between 12 and 14 and doesn't change between highway or city either. I have always just figured it is the weight combined with the rolling resitance of the truck that causes the fuel hit that the 1 ton has verse the 2500. I have driven other 2500's and you are right about the differences between how they drive, everytime I drive one it's almost like I'm in sports car instead of a truck compared to our 3500. The difference is really remarkable, add two tires and 1000lbs and you have a completely different beast. John

Trevor, you stepped up out of the bullpit into the Big League bro', of course you are going to have some operating and performance changes from a 2500 to a 3500. ;) But you gained soooooooo much more IMHO! :ro)

I wish I had kept all the posts I read from back in 2002 where guys were having soooo many problems their LB7's problems. Now that is has been superceded by the LLY it is the best engine ever! ):h I suspect the LLY will go through many of the same iterations as the LB7 getting all of its bugs worked out. There is no such thing as an unbreakable, problem free piece of machinery! :confused: It does appear the GM boys went to school on the LB7 when designing the LLY though.

I pull a 40' 5ver that usually weighs in around 15-16k lbs, couple of times I have loaded it to 18k lbs which is GVWR, GCW around 25k lbs. The footprint the dually has on the road is great, eeeerrrrrr except in snow (dangit:eek: ).

My LLY started out around 15-16 city, 18-19 highway, then dropped to around 13-14 and 15-16 respectively. I only have around 11k miles on mine so it is still breaking in. I just had the truck reflashed and mpg's appear to be better: 22.84mpg highway on my first tank :D . I'll check it again in a few weeks. I don't bother with calculating city mpg's in the colder months since I remote start and let the LLY run for 10-15 minutes before leaving home in the a.m.

Since the reflash the truck also idles smoother, power range is smoother, and towing improved. My truck used to downshift going up/over hills and overpasses, it doesn't do it anymore.

The more you drive it the more you will love it. Later! JJ :)

Drive a Ford Crew Dually 6.0 with the Torqshift.
It will knock the socks off a Dmax dually.
I drove one a couple months ago. Incredible acceleration for a dually.

Don't forget about tire size on the 3500 cuts into fuel mileage over the 2500s.

not sure what the dually weight is, but my 2500with the aux tank is in the 8300llbs area, and still will do a 14second 1/4 mile range, as for mileage it is right in their with the best, as for pulling, holiday trailer is 9k an no problems, so i guess i will stay with the 2500,for my style

Hoot states: "Drive a Ford Crew Dually 6.0 with the Torqshift.
It will knock the socks off a Dmax dually."

Hoot, you know better than throw the ole "Ford vs Chevy vs Dodge" bone out there! ):h Ever since you became a Dodge boy, nothing but trouble! :p So we'll sit back and wait for the dozen or so "My Duramax blew a PSD's doors off" OR "My Ram ate the Duramaxipad for lunch today" OR "My stroker pounded some Ram and Duramaxipad bootee today" stories! :rolleyes:

Guys with dually's are posting a wide range of mpg's. My personal experience is MPG's are more a consequence of keeping my foot out of the accelerator as well as keeping the RPM's down moreso than tire size or extra wind drag of the bubble butt. If I drive conservatively on the highway, say 65mph, I consistently hit a minimum of 18-19. Since the reflash I hit 22.84mpg, but since that was only a 80 mile run I don't consider it accurate. More testing to come! :o

The colder weather also makes it harder for the LLY to get up to its optimum operating temps which will adversely affect mpg's. JJ :)

I would like to know what happens with the reflash, I posted on another thread my going to the stealer for warranty work three times my mpg dropped started 20.5 dropped to 18.9, the last time I ask for another tech to do the work, as I had words with the first about his work( he left power steering fluid all over engine area, & he had the attitude,he wasn't going to replace turbo intake pipe, because it would't affect engine performance, short of it I called GM theyt had it replaced.) the third time I asked for another tech, now my fuel has dropped to 17.8. would a reflash help mpg & could a tech do something to lower mpg



Trevor, you stepped up out of the bullpit into the Big League bro', of course you are going to have some operating and performance changes from a 2500 to a 3500. ;) But you gained soooooooo much more IMHO! :ro)

I wish I had kept all the posts I read from back in 2002 where guys were having soooo many problems their LB7's problems. Now that is has been superceded by the LLY it is the best engine ever! ):h I suspect the LLY will go through many of the same iterations as the LB7 getting all of its bugs worked out. There is no such thing as an unbreakable, problem free piece of machinery! :confused: It does appear the GM boys went to school on the LB7 when designing the LLY though.

I pull a 40' 5ver that usually weighs in around 15-16k lbs, couple of times I have loaded it to 18k lbs which is GVWR, GCW around 25k lbs. The footprint the dually has on the road is great, eeeerrrrrr except in snow (dangit:eek: ).

My LLY started out around 15-16 city, 18-19 highway, then dropped to around 13-14 and 15-16 respectively. I only have around 11k miles on mine so it is still breaking in. I just had the truck reflashed and mpg's appear to be better: 22.84mpg highway on my first tank :D . I'll check it again in a few weeks. I don't bother with calculating city mpg's in the colder months since I remote start and let the LLY run for 10-15 minutes before leaving home in the a.m.

Since the reflash the truck also idles smoother, power range is smoother, and towing improved. My truck used to downshift going up/over hills and overpasses, it doesn't do it anymore.

The more you drive it the more you will love it. Later! JJ :)

Yeah, I, too, remember some of the initial problems when the LB7 came out. I have a friend that will not own another Duramax to this day because of his bad experience with his '02. He bought it used, and the dealership ended up buying it back. It was broken down more than it ran. He bought an '02 Dodge dually just to tear the transmission up and crack the block! I drove the wheels off of my '03 with absolutely no problems whatsoever. The '05 came along since we wanted the year-end write-off and no clearance problems with the trailer when turning. I'll probably throw a Magnaflow cat-back on the truck this week and follow with an Edge Juice w/ Attitude shortly.

I've been a GM guy all of my life, but I did give Ford the benefit of the doubt. I went and looked at them but was not overly impressed. The Duramax treated me great in the '03, so I didn't want to screw up a good thing. :) The Fords are nice, but we couldn't show up at a Corvette or Camaro/Firebird race pulling our GM cars with a Ford. ;)

On a side note, I have noticed that the LLY does not run the glow plug near as much on cold starts as my LB7 used to. It was three degrees here last Friday morning, and the LLY did not take anywhere near the time before firing. It was also much quicker to fire off than my LB7. The LLY also seems to reach operating temp quicker than my LB7.

Overall, I'm very pleased thus far. Granted, I've only had it four days, but I've already put over 1,000 miles on it. :)

Trevor

Chickentruck, don't ever underestimate anyones ability to totally hose up these new trucks. :o There are several good techs on the forum that I would not offend for anything, they've provided us all with invaluable information and assistance. However, these are state-of-the-art diesel engines and my experience to date with the average dealership service techs is the training is lacking, seriously lacking! Keep in mind I'm one seriously meck-a-nickel-ally challenged guy and I find myself using the knowledge I gain on this site to advise them on how to perform certain procedures. IMHO find a good dealership/tech and stick with them, even if it involves driving a bit. I commute from Jacksonville to Daytona Beach for service, about 70 miles one way, but I trust them to do what I tell them to and not pork me on the bill. :(

As for the reflash that is something one of the techs will have to speak to. All I know is since the reflash my mpg's are up, my LLY runs smoother/quieter, and the drivetrain just seems to operate better all-around throughout the entire gear range. I have read another post where someone lost power after the reflash. Best to read through the forum and decide for yourself.

Trevor, congrats on the truck. At 1000 miles it may be too early to put too much stock into the mpg's. They will get better as everything breaks in and you keep good lubrication in it. As more mods and programmers are coming out for the LLY I'm seeing more former LB7 owners sounding like their "sh__t eatin" grins are coming back on their faces. All in all the LLY appears to be a pretty decent 1st year production engine.:ro)

As for engine temps, the LLY gets up to operating temps quicker likely compliments of the EGR and dual tstats. Some have disconnected the EGR, there are several post on the subject on the forum. Later. JJ :)