[n0useforaname]

I just bought and 07 Classic Duramax 6.6 with the Allison tranny. And there are ALOT of things the internet and GM can't answer for me. First off..what is the difference between the LBZ and the LLY? And how do you tell which one you have? Second...should I be using fuel additives? Do they really help that much. Third...I don't really have a led foot. Is it bad to (baby) a diesel engine? Or should I be giving it [email protected]%%? And Finally....do the 07's have the 06 engine in them? And are they compatible with low sulfur fuel? Any help on ANY of these questions would be great...I've talked to 7 different garages from PA to SC and NONE of them knew what to tell me.

 

[TYREBOYZ_DEMAXIN]

first off,the way to tell witch engine you have using the vin # is by counting right to left and the 8th didgit if it is a
1=LB7,used 01 thru 04
2=LLY,used 04.5 thru 05
3=LLY,used in early 06
D=LBZ,used 06 thru 07
6=LMM,usied 07.5 thru ?
i'm not sure on the LMM but i believe that is the right #.

yes i use amsoil diesel additive with every tank and would recommend you do the same or some other diesel additive that will do the trick,the reson is with this never ULSD it doesn't have as much oil in it to lube the internals of engine like it use to plus this additve helps keeping your injecters clean and takes care of the water issues..
there main difference between the LLY and the LBZ is the computers and they have upgraded the colling system for the LBZ seeing they had some overheating problems on the LLY,here is a link to a thread from this site with some good info http://www.duramaxforum.com/forum/04-5-05-lly-duramax-powertrain/1837-lly-lbz.html
on the breaking in part,well there are sevaral different ideas on this subject and here is a link to thread that somebody else asked the same question so i would recommend reading it and going from there http://www.duramaxforum.com/forum/06-07-5-lbz-lly-duramax-powertrain/1712-break-new-truck.html
good luck and keep us posted
ps quick ? do you plan on doing some aftermarket goodies?

 

[n0useforaname]

Cool

Well I've established that I have a LBZ. And I was looking at the Amsoil stuff...it's seems inexpensive and I'm going to try to pick some up today. And as far as doing any mods....I'm going to wait a bit. I have a 100,000 mile warranty on my truck...and any engine mods will void my warranty...and my wife would destroy me. I did get a billet grill, running boards, and a tonneau cover for it. Doesn't help the performance...but it makes it look better! Thanx for helping me out. But as far as the breaking in part goes...I'm not worried about the initial break in...I'm talking about whether I have 3,000 miles or 100,000 miles, should I be thromping on it, or doesn't it matter? I'm just not sure how a diesel engine works...I want to get a long life out of this truck...and with a gas engine..if you baby it...it lasts longer.

 

[ob_1jr]

Welcome to the site! Diesel engines were made to be worked. I feel that you have to get on it every so often if you are not towing all the time. I don't think that you will hurt the truck by babying it, but you won't hurt it if you drive it like it was stolen as long as you don't have a lot of power adders. Keeping your foot out of it will definately give you better mileage. For me, the mileage doesn't change a whole lot by the way I drive, so I just have fun and use the hp/torque that I paid for. You will love your truck. Amsoil is good stuff and if easily available in your area, would be great. I personally use Stanadyne fuel additive mostly for piece of mind. I have been through 3 winters here in Alaska's interior with -50F days and have had no problems with my truck starting or gelling up.

 

[idrivebowtie]

well i live in southern california and it never gets below the 40's and i have never had a problem. and i drive the truck really hard