I have been a regular here since late 04 and the lack of any real issues so far from the forum about the LMM, other than the REGEN is making me feel better about trading my 05 for the LMM. I think that we need to keep posting, but any regulars to this forum will see that to date nothing serious has been listed about the LMM trucks.

I was one of the lucky ones with my 05 and all I had to deal with was the things under GM'S recalls when I traded with 35,956 miles showing.


I hope that we are all still talking about the same old topics this time next year. I have 3000 trouble free miles to date and nothing to complain about other than the regen. I love the new interior and the 6 speed Allison.

Jim

Man Im a classic guy but it sure is good to see that GM actually did their homework all the way through before they marketed that beast.
Glad to see everyone is enjoying their new trucks, I LOVE the interiors.

i have 1400 miles on mine already.....I am a big fan....no complaints so far...

Got over 4600 miles in about 5 weeks so far and no issues yet either. I myelf glad I waiting for the new style. Needed a change of interior. Had the same interior since about 1999.

Brian

All good from my end as well. Happy with mileage, performance, ride, fit and finish!!

If most folks start reporting 21 MPG running empty on the highway at 65 or 70, it will get me thinking about moving to the LMM. I haven't seen the fuel economy I'd want yet, maybe it's coming when they have more miles on them.

lmm's are great, every gen of the d-max has been more trouble free than the last...at least thats how it seems at my dealer...

If most folks start reporting 21 MPG running empty on the highway at 65 or 70, it will get me thinking about moving to the LMM. I haven't seen the fuel economy I'd want yet, maybe it's coming when they have more miles on them.

Don't buy that 21 MPG stuff not going to happen to all of them if any. I am happy with my 11.2.

Nice truck though.

Im seeing 16.5mpg max, got only about 500 miles on her though. I love my white chevy LMM need to get her lifted like noproblem though.

I agree... No major problems and I am happy with my mileage, power, fit, finish, etc...

My milegae is 14-15, although I must have hit a regen because the mileage started dropping while easy driving and leveled off at 13.6. After driving about 30 miles or so it is now on the way back up.

I only have around 450 miles now.

2900 miles and no problems

3000 trouble free miles. 18.5 at 70-75. 9.7 towing 25 foot fifth wheel and 20 ft. lund boat at same time at 65-70. awsome truck :D

Good luck 11.5 mpg????? waht kind of driving do you do. I fully realize they are 8000 lb trucks that thats not good if your empty. I think its too early still to call them 100% success, but nice to know so far no problems. Once somone gets 250,000 trouble free miles on it then its a success.

I got my truck back in april and its been great!! i got about 2000 miles on it and i get 14.6 mpg which is good. But most of all i love the power!!! i raced a 06 ford f350 the other day and ripped him a new one!!!! and its all stock. I left two fat tire marks on my street!heheheheh -belsin

I have over 5,400 miles on my LMM. First diesel ever.
Mileage is outstanding from my perspective. Overall I am getting consistently 18.1-18.3 hand calculated. My driving is 2/3 to 3/4 highway, remainder local. On the highway the DIC is showing 20 at between 65mph-70mph. For reference purposes, the DIC is showing 19mpg overall when hand calculated is between 18.1-18.3mpg. No complaints at all. Interior is superb, handling for such a large truck is great & acceleration & power are excellent.

I have only had my LMM a few days, but drove it over the cascade mountains nearly 300 miles, mostly at about 65 mph, averaged 18.7 mpg. I reset the DIC for my commute the last few days back and forth to work on level freeway at 65-70 and am averaging right at 21 mpg. For a new engine, I am pretty dang happy with that. The average will be pulled down by town driving, but I think under regular circumstances 20 mpg on the freeway is certainly attainable with this truck.

I have about 2300 miles on my new lmm. Took highway trip when two weeks old stayed at 1500 rpm's 60 mph and got 24 mpg. Usually drive 70-75 on highwat and get around 20 mpg. Towing 10,000 lb. trailer I got around 12 mpg. No major issues with truck no minor ones either now that i think of it. fit and finish is great and would buy another if the need arose.

No major issues so far but the towing is a bit questionable. Not powerwise (which is no issue) but the back end is loose.
My good friend had an 05 Duramax with a 6" lift and it pulled his 28' boat like it was on rails. He now owns a brand new 07.5 LMM with the same lift and tires and the tail-end pushes around in turns to the point of being uncomfortable.
I have just bought an 07.5 LMM and installed a 6" lift and when towing our 35' boat I get the same very uncomfortable feeling in the turns. I just came from and 01 PSD F350 with 6" lift and it had absolutely no looseness.

I understand that apparently nothing has changed from 05 to 07.5 but apparently it has.

I have been in contact with Tom Frederico about sway bars for the front and rear but I am still questioning why I have to spend another $500 when I just bought and HD truck with a Duramax for $45k???

Don't get me wrong, I love the truck but I would have expected better tow handling.
(note: We are very hitch savvy and are very conscience of tounge weight)

Dave

Anyone having issues towing when they are stock?

No major issues so far but the towing is a bit questionable. Not powerwise (which is no issue) but the back end is loose.
My good friend had an 05 Duramax with a 6" lift and it pulled his 28' boat like it was on rails. He now owns a brand new 07.5 LMM with the same lift and tires and the tail-end pushes around in turns to the point of being uncomfortable.
I have just bought an 07.5 LMM and installed a 6" lift and when towing our 35' boat I get the same very uncomfortable feeling in the turns. I just came from and 01 PSD F350 with 6" lift and it had absolutely no looseness.

I understand that apparently nothing has changed from 05 to 07.5 but apparently it has.

I have been in contact with Tom Frederico about sway bars for the front and rear but I am still questioning why I have to spend another $500 when I just bought and HD truck with a Duramax for $45k???

Don't get me wrong, I love the truck but I would have expected better tow handling.
(note: We are very hitch savvy and are very conscience of tounge weight)

Dave

I am curious, did you try towing with your truck prior to installing the lift?

With the installation of a lift, I would think all of the dynamics engineering just went out the window.

I've noticed mileage numbers all across the board. I've had 20mpg in an all highway tripp that ranged from 55 - 70 (depending on the speed limit). I got down to 15 running 80mph. Right now with my normal driving, Im at 16.8. One thing I know for SURE is that these things are worse on wind than my last one.

If the wind is blowing you can forget about speed + mileage. If the wind isnt so bad it would seem you can have your cake and eat it too. Thoughts?

I am curious, did you try towing with your truck prior to installing the lift?

With the installation of a lift, I would think all of the dynamics engineering just went out the window.

No... But I can't really buy into that theory considering the past experiences with an 05 Duramax and F350 both lifted with no issues. It seems to be "new body style" related for some reason.

Dave

I've noticed mileage numbers all across the board. I've had 20mpg in an all highway tripp that ranged from 55 - 70 (depending on the speed limit). I got down to 15 running 80mph. Right now with my normal driving, Im at 16.8. One thing I know for SURE is that these things are worse on wind than my last one.

If the wind is blowing you can forget about speed + mileage. If the wind isnt so bad it would seem you can have your cake and eat it too. Thoughts?

Is it me or is the wind always in our face :p: ;)

I have had 3 regens to date and mileage drops about 1.5 on the dic when it goes rich ,injecting fuel on the exhaust stroke ,to fire off the soot

I have had 3 regens to date and mileage drops about 1.5 on the dic when it goes rich ,injecting fuel on the exhaust stroke ,to fire off the soot


I am beta testing for Edge Products and it actually tells me when it's in regen. Just curious, how can you tell otherwise?

When mine goes into regen, it stays in that mode during slow neighborhood driving and idle as well as highway driving. This is contrary to other reports. My EGTs do however rise to ~1100 around the neighborhood during this time.
It last for about 20 minutes and then is done.
I wouldn't be able to tell if I didn't have the Juice/Attitude unit.

Dave

NordicFlame,

To answer "How can you tell when truck is in regen without Edge?"

My DIC tells me.

All of a sudden AVG. MPG for no apparent reason starts to drop and quite fast. When over, my DIC tells me by a slow increase in AVG. MPG.

I am a person who resets his DIC, everytime he fills up. This way I know how I did on that tank of fuel.

Tach will move mid way between center and 1,000 rpm's when regen is happening.Mileage on dic drops fast and somtimes when exiting the vehicle there is a strong burning odor.The regen,when interrupted resumes when restarted.I parked overnight and it resumed the following morning and does take about 20 minutes to complete.

As for the towing Q... yes lifts can affect towing, the lift blocks exaggerate the forces acting upon the leaf springs. A 6" kit has roughly 4.5" blocks... A 4" kit has 2.5" blocks.

I have 3.000 miles on my stock LMM, no major problems and she tows like a beast. I tow my 37 ft. 5er which weighs in at around 13k and feel very stable around turns and up hills. I do believe that the new body style does have a higher bed height which might lend to the hitch being set up differently than in previous years. As you increase the height of the pin you take weight off of the front of the trailer and load the rear trailer springs up more than before... just a thought.

I just did my first oil change tody as well as the front and rear end gears and the alli spin on filter, no sweat.

Anyone having issues towing when they are stock?


I have 6000 miles on mine, 4door, and tow a 24ft deckover, tag style hitch with a 1976 chevycrew cab with a 6.2 offroad truck onit.. and I think it tows and stops turns great.. only problem I have had is the park assist has not worked since about 50 miles, haven't taken it back yet.

I'm at 6000 miles now and I still have no issues with my truck. I will be taking it to Myrtle Beach this week so I will put about 1500 more miles on it for this trip. Mileage seems to be improving as the miles accumulate!

Jim

4000 mis not one complaint. BTW, I tow a 10,000lb boat w/ just the front leveled and have no issues w/ the handling at all

I'm at 33000 miles on my LMM....and its been absolutely flawless...:cool:

I hope that this is the kind of service that we all have to look forward to in the future. So far it looks like a great truck!

Jim

My wife and I are looking at pulling the trigger on an '07 GMC LMM. Never had a diesel before. Anything I should be looking for at the dealer or after I pick it up? Is it true that if I try to load up a different "tune" into the ECM for the engine, the ECM will "tattle" on me when the truck is plugged into by GM? What is this "regen" thing I keep reading about???

I have 16000km on mine and it's been great.

I have 7,000 miles and absolutely no problems. I really like this truck and may end up being my all time favorite vehicle. Fit finish is un-truck like. Paint way better than my vette. I cannot say enough good things about this truck.

Towed a 14x7 box yesterday. 380 miles. 11.7MPG.

Normally I get 16.5 MPG on LLLOOONNNGGG checks (I check MPG in a 1,000 mile increment). Really, as of yet, haven't seen any MPG improvement over new. With 7k miles it makes me wonder. But... I am not one to worry about MPG. I buy and drive.

I have LTZ and interior is really nice while driving. Such an improvement over old interiors.

I have around 2500 miles and no problems what so ever….
I pulled a 10000 lb TT twice and LOVE the power.
Miles are 20 hwy, 16 city, and 11 pulling…
The only thing I want to change are the tires, 245’s look retarded.

I have 4600 miles on it, have had no problems at all. 13-16 mpg depending on
what i'am doing. 10-11.5 towing a 28ft tt.Love the power when towing over my
2002 1500 gmc z71. Its a keeper!!!!

I have around 2500 miles and no problems what so ever….
I pulled a 10000 lb TT twice and LOVE the power.
Miles are 20 hwy, 16 city, and 11 pulling…
The only thing I want to change are the tires, 245’s look retarded.

They do look stupid but thats how you get those high MPGs. My truck is 2-3mpg lower than you w/ just a 33" tall tire.

They do look stupid but thats how you get those high MPGs. My truck is 2-3mpg lower than you w/ just a 33" tall tire.

Force of rolling resistance is a function of tire coefficient of friction and total vehicle weight (that includes the weight of the tire itself).

Tire coefficient of friction is a function of tire radius, width, tread pattern, tire pressure, temperature of the tire, and type of tire compound used.

Long story short, you put big off-road meats with a soft compound on a big truck, expect to have to work harder to get down the road. If you have to worker harder to get down the road, down goes the mileage.

Sorry to say, great as GMC D/A setups are they still have to follow the laws of physics like everyone else :rules:

Sounds like the cams in your new generation engines were made by Asimco in Grand Haven Michigan. We made all the Dmax cams up to May of this year. I'm curious to see how they hold up after that. We went bankrupt in May of this year and ceased production at that time. It will be interesting to see if the new cams will be as good as the cams we made. We were good at making cams, we just weren't good at selling them for enough... In fact we sold the Dmax cams for under $40 bucks to Dmax...
Oh well... good luck with your new cams!

The LMM is a 4th generation motor. The bugs should be out of that bad boy by now. It is basically a LBZ with the emission crap on it, so you really should not have had any problems with the motor.

Sounds like the cams in your new generation engines were made by Asimco in Grand Haven Michigan. We made all the Dmax cams up to May of this year. I'm curious to see how they hold up after that. We went bankrupt in May of this year and ceased production at that time. It will be interesting to see if the new cams will be as good as the cams we made. We were good at making cams, we just weren't good at selling them for enough... In fact we sold the Dmax cams for under $40 bucks to Dmax...
Oh well... good luck with your new cams!

Hello, Cammaker. Sorry to hear about the Chap. 11 and plant closings. I've been where you are... have been through 10 jobs in the past 16 years myself. Some I left on my own terms, some I got caught in the crossfire. One thing I've learned is that life goes on. If you can pick yourself up one more time than you've been knocked down, and you watch over those you love through thick and thin, then you're living your life as a man should. Hope you've been able to find a new job quickly and, if still looking, our hopes and prayers go out to you.

It looks like Linamar (which took over cam production from Asimco) has been around for a long time. Asimco is pretty much a Chinese company, whereas Linamar is based out of Canada (Ontario) with a presence covering NA, Europe and Asia. Have you tried to get on board with Linamar or one of their holdings?

Seriously, best of luck to you and hope that things work out.

Thanks for your well-wishing... I had a job before the doors closed... So I was ok... Actually when we started to make the cam we were not Asimco, we were Federal Mogul. The program was originally launched in Orland Indiana but consolidated to Grand Haven Michigan a while back. Asimco purchased our plant for a song after Federal Mogul went bankrupt. I was the Engineer over the Dmax program for several years. We had very few Customer returns over the years with this cam. I could mention a few but it's really not worth it. Overall this cam was well designed from the get go. After july of 2003 there was an extra oil groove added to one of the journals to throw extra oil into the turbo charger bearings. Personally I'd buy a Dmax built between Aug. 2003 and May 2007 to get the best cam. I spent a lot of time at the Dmax plant in Ohio so I am quite familiar with some of the challenges they faced. Out of all the engine plants I've been in over the years I'd have to say that one is first class. Asimco is owned by Jack Perkowski who is an American who now lives in China...

I'm willing to give the new cam maker a chance before condemning them. It's the fair thing to do. I'd be surprised if GM would risk the Dmax reputation by switching without a lot of checking. I ordered an 08 LMM last Tuesday. That's my interest.

Dmax had no other choice than to resource this program at lightning speed. Asimco did not give them much warning or time when they announced they were closing their doors. I spoke with the Engineers at Dmax during this process and believe me it was pure ugly at Linamar during this time. Everyone was on pins an needles... 80+ hour weeks... 7 days a week. A word to the wise! I'd give them 6 to 8 months if I were you... Not trying to be a pessimist just trying to enlighten you on how things were without spelling out too many of the gory details. I just want you to make the best purchase with the best chance of having a long problem free period of ownership. Take it for what you will...

Jim I agree with you :cool: I only have 2700 or so miles but I dont even know if I had a DPF yet. Otherwise this truck is a wonderful truck and I expect to have it for some time... Last truck was a 1996 7.3L... just traded it in on this one.
Glad I did...

BSAH:D
Dan

only problem I have had is the park assist has not worked since about 50 miles, haven't taken it back yet.

Dont leave your Ball Hitch in... believe it or not, the system can see it. :eek: Mine quit working about a week ago and then I remembered that there was a change... I had left the ball hitch in because I got a lock for it a few days prior. It only stands off of the bumper about 4 inches and I didnt think it would be an issue but I took out the Reese stinger with the 2" ball on it and TADA... it started working again... that easy.

Just my experience and YMMV... :D

BSAH
Dan