Hello, I'm new to the forum, and have to say I have already learned so much by reading all of your posts...Thanks!

I currently have a Chevy big block, and within the next month will be buying a new GM diesel. There are a few questions in my head that I need help answering before I make my purchase.

I will be buying an 07 2500HD, CC, 4WD. Not sure if it will be the classic with the LBZ, or get into the LMM. I drive roughly 15,000 miles per year. 60% city, 20% hwy, and 20% towing a 7500 lb travel trailer.

Question # 1. 3.73 vs. 4.10 gearing. Most of my driving isn't towing, so the 3.73 would be nice for mileage. When I am towing my travel trailer would I have wished i went with the 4.10, or would I still be tickled pink towing with 3.73?

Question # 2. When the LMM goes into regen does it lose power, and if so would it be enough to be concerned about if it happened while going up grade in the mountains pulling my travel trailer?

Question # 3. Most days I am only driving 4 miles one way to work and back. Speeds of 30-45 mph. I understand the LMM regens about once per tank, for 20-30 minutes, and will initiate when runnings speeds greater than 30mph. Would the LMM ever really get a chance to regen itself with my driving habits, and if so would it ever have a chance to complete?

I would appreciate any insight that can be given to help me answer my questions. Also, any other insight that would help me decide between a LBZ and a LMM would equally be appreciated. Thanks!

I can't give any advice on the LMM questions but I believe that 3.73 is your only choice for a duramax. It has more than enough power with 3.73 gears to do anything you would need.

my 03 with 3.73 tows great duramax ally cc dually 2wd. In my 07 kodiak 4500 as for the regen loosing power I have not noticed it any during towing or normal driving and I have a light that lets me know what stage it is in, in the kodiak. In my rig you can do a maunual regen as well in idle with the truck running I have a switch that I can hit. seems that the regen gets faster each time on its own though instead of the 20-30min cycle.

Question # 2. When the LMM goes into regen does it lose power, and if so would it be enough to be concerned about if it happened while going up grade in the mountains pulling my travel trailer? The engine will not lose power. There should be no concerns if happens towing a trailer. [/COLOR]

Question # 3. Most days I am only driving 4 miles one way to work and back. Speeds of 30-45 mph. I understand the LMM regens about once per tank, for 20-30 minutes, and will initiate when runnings speeds greater than 30mph. Would the LMM ever really get a chance to regen itself with my driving habits, and if so would it ever have a chance to complete? You should not have a problem, if you live in a warm climate. If you live were you have very cold winters, then you will need to make a freeway run if you see the Clean Exhaust Filter message.

$3,250 Cash Back on LBZ's right now per GMC website. I don't think you would ever have a problem getting some good money out of an LBZ if you ever sold it.

I drive my '93 Accord to work because it is 50 miles round trip. It also nice not having to worry about some A-hole bum downtown screwing with my rig overnight. I drive my new LBZ when I'm off work. I'd rather rack my miles up when I go playing on the weekend or on my scouting/hunting trips.

If I was only 4 miles from work, I'd ride a bike or run to work when the weather is nice. But then again...its awfully hard not to jump in the D-max for the obvious reasons.:)

you can only get a 3.73 if you go any higher like 4.10 it would suck fuel and you would get like 8 mile to the gal.

If I was only 4 miles from work, I'd ride a bike or run to work when the weather is nice. But then again...its awfully hard not to jump in the D-max for the obvious reasons.:)

Thanks for the reply. I did have an older car I used for running around town. The problem I had was with my occupation I have some equipment that I have to have with me 24/7. It really got old transferring the equipment back and forth between vehicles.

That rebate for the LBZ is hard to overlook. Thanks again.

I have the LLM and I cannot tell when it goes into regen, but I think it has a few times. There were a few stickers on the exhaust pipes and DOC that smelled bad when they were getting cooked off, on what I believe was a regen. There is no noticeable loss in power.

What is regen? And is it just the LMM or does it occur on LBZs as well?

New diesel owner here.

Thanks for the reply. I did have an older car I used for running around town. The problem I had was with my occupation I have some equipment that I have to have with me 24/7. It really got old transferring the equipment back and forth between vehicles.

That rebate for the LBZ is hard to overlook. Thanks again.

That $$$$$$ could be a canopy, a new set of tires, a Nicktane fuel filter and a Oil-Bypass:D

What is regen? And is it just the LMM or does it occur on LBZs as well?

New diesel owner here.

From Wikipedia:

A diesel particulate filter, sometimes called a DPF, is a device designed to remove diesel particulate matter or soot from the exhaust gas of a diesel engine. Wall-flow diesel particulate filters usually remove 85% or more of the soot, and can at times (heavily loaded condition) attain soot removal efficiencies of close to 100%. A diesel-powered vehicle equipped with functioning filter will emit no visible smoke from its exhaust pipe.
In addition to collecting the particulate, a method must exist to clean the filter. Some filters are single use (disposable), while others are designed to burn off the accumulated particulate, either through the use of a catalyst (passive), or through an active technology, such as a fuel burner which heats the filter to soot combustion temperatures, through engine modifications (the engine is set to run a certain specific way when the filter load reaches a pre-determined level, either to heat the exhaust gases, or to produce high amounts of NO2, which will oxidize the particulates at relatively low temperatures), or through other methods. This is known as "filter regeneration." Fuel sulfur interferes with many "regeneration" strategies, so almost all jurisdictions that are interested in the reduction of particulate emissions, are also passing regulations governing fuel sulfur levels.

jd524 Don't. Stick with your big block gasser. It is more than ample to handle your trailer. Diesels are expensive to buy and expensive to own. Check the price of a fuel filter. Short runs are bad on any engine, worse on a diesel. In small rural communities diesel is not always available. Old diesel tanks often have water in them, a serious problem in your neck of the woods. Ethanol in your gasoline prevents this problem with gassers.

jd524 Don't. Stick with your big block gasser. It is more than ample to handle your trailer. Diesels are expensive to buy and expensive to own. Check the price of a fuel filter. Short runs are bad on any engine, worse on a diesel. In small rural communities diesel is not always available. Old diesel tanks often have water in them, a serious problem in your neck of the woods. Ethanol in your gasoline prevents this problem with gassers.

I don't believe he asked IF he should buy a diesel, but rather info on what he's looking at.
Q: What rural communities don't have diesel??? A: The ones that don't have gas either.

Get a diesel best thing I ever did!

get the diesel for pulling, longevity, mileage, resale value. They cost more, they are worth more. take 0% on the LBZ if you an get it, this will save you much more than the rebate over the life of the loan. The LMM s a few grand more than the LBZ for the body style and more emissions. Pick what you like. I don't think you can go wrong with either truck as long as it's what you want.

Thanks to everyone for all of their insight. I think I will go with the LBZ, save a few grand and use the money to add a few mods to the truck. Thanks again.