Recently I read an article in an automotive magazine that stated that the 2006 Duramax/Allison was the best year for the Duramax/Allison? It said that in that year the engine made more horsepower and torque than any other year between 2000 and 2013? This was due to the environmental requirements from the government that begin in 2007. It also said that the 2006 had a 6 speed Allison transmission and got better fuel mileage both towing and empty than other models?I am interested in hearing from anyone that has any experience with the 2006 Duramaz/Allison combination. I would like to know what kind of mileage they get towing an RV and what kind of mileage they get empty on the open road? Thanks for your information.

The 2006 and early 2007 (classic) Duramax Allison LBZ generation is considered to be an excellent combination..It has proven to be very reliable and relatively trouble free.Lots of power with very few EPA mandated 'environmental protection' systems.Later generation motors do have more horse power and torque but also have a number of systems that are designed to reduce emissions...some which have been problematic and have reduced mileage.I get around 12 sometimes less towing a 10K GVWR trailer and around 14 mpg mixed daily driving...have seen a tick over 22 straight cruise control freeway long runs.If you can find a clean 06 D/A consider it. They are hard to find and sought after.

If you find a 2006 or 2007 it would be a good purchase as noted above.Traded my 2005 for a 2011 because of the increased GVWR, exhaust brake, more HP/Torque, integrated brake controller and 6 speed Allison. Have a little over 21,000 miles on it without any issues.

Almost everything they said about the LBZ is true except the HP and torque. The later years had more depending on year.I get right at 12 towing my 7K TT. I'm grossing somewhere around 16K.I run fast when I'm on vacation because I have to just to cover the miles I need to. I'm usually at 75mph towing on the freeway. I bet I could get 13+ if I slowed down to 60.Solo I get 16.5 to 17. This is mixed town and open road but mostly town.Ric, your phone is ringing. :B

I get 11.5 MPG towing my 5W (about 14K GVW) at 62 MPG (speed at which the TC locks up in 6th gear).Around town I get 13 MPG and 20 MPG at 65 on the Interstate when empty.I have 65K on the ticker right now but will bump that up significantly as leave for AK on Thursday. My LBZ is the first diesel I've owned. Have had minor repair issues with GMs el-cheapo tranny hoses leaking at the crimps and the replacement of 1 glow plug. My intention is to keep my '06 D/A until someone has to pry it out of my cold, dead hands.

21 mpg unloaded 190 mile round trip highway and some city driving.Loaded varied by weight and design of trailer being towed. But it was very good.

2006 Chevy Duramax/Allison Question? | Good Sam Community

N-Trouble
Explorer
May 28, 2013
Tystevens wrote:
Vroadracer wrote:
I thank everyone for your comments on the LBZ model of the Duramax. I found an early 2007 GMC Sierra Classic with the LBZ engine in it and the truck was in very good condition. I drove the 830 miles from Tennessee to Houston, TX to get it and was pleased that it got 22mpg on the way back to TN by me keeping it under 70 most of the time. About 150 miles of that was in severe rain and wind in the left over effects of the storm that hit Oklahoma City.

I noticed that it does not lock into 6th gear until it gets to about 62 MPH. Will it be a problem to tow my 14,000 lb 5th wheel in 6th gear out on the open road, or do I need to keep it in 5th gear manually?
Thanks for your comments.

I would just leave it in D, tow haul engaged, and let it do its thing. As long as it isn't hunting between 5 and 6 (which is probably wont), there should be no issue.

Actually, I would set the cruise at 64, let it shift into 6th, and enjoy moving along at 1700 rpms!

Good luck!

Agree. Too many guys think they are smarter than the Allison...LOL. Just put it in D with Tow/Haul engaged and let it do its thing.
N-Trouble
Explorer
May 28, 2013
Towing is not all about the motor... Putting the motor aside for a minute its also worth noting that the 2011+ GM HDs are a whole new beast when compared to previous versions. Hell the back brakes on my 2012 are bigger than the front brakes were on my 02. Not to mention the bigger frame, beefier front end components, bigger rear axle, and don't forget the all important exhaust brake the new platform tows so much nicer than the older models.
Vroadracer
Explorer
May 28, 2013
I love my LBZ engine in the 2007 GMC Sierra Classic. It averaged 22.0 MPG coming home from Houston, TX when I bought it. I took my first trip pulling my 37 ft Cardinal 5th wheel and I averaged 11.11MPG towing. I followed the suggestion to leave my rig in the Tow/Haul mode at about 62 mph and set the cruise control and let it shift when it wanted to and that seemed to work well in the area where I was towing. It may be a different situation in mountains when I head North in 2 weeks. I am enjoying the extra torque and horsepower that the 2007 has over my 2002 Duramzx.
Tystevens
Explorer
May 22, 2013
Vroadracer wrote:
I thank everyone for your comments on the LBZ model of the Duramax. I found an early 2007 GMC Sierra Classic with the LBZ engine in it and the truck was in very good condition. I drove the 830 miles from Tennessee to Houston, TX to get it and was pleased that it got 22mpg on the way back to TN by me keeping it under 70 most of the time. About 150 miles of that was in severe rain and wind in the left over effects of the storm that hit Oklahoma City.

I noticed that it does not lock into 6th gear until it gets to about 62 MPH. Will it be a problem to tow my 14,000 lb 5th wheel in 6th gear out on the open road, or do I need to keep it in 5th gear manually?
Thanks for your comments.

I would just leave it in D, tow haul engaged, and let it do its thing. As long as it isn't hunting between 5 and 6 (which is probably wont), there should be no issue.

Actually, I would set the cruise at 64, let it shift into 6th, and enjoy moving along at 1700 rpms!

Good luck!
Vroadracer
Explorer
May 22, 2013
I thank everyone for your comments on the LBZ model of the Duramax. I found an early 2007 GMC Sierra Classic with the LBZ engine in it and the truck was in very good condition. I drove the 830 miles from Tennessee to Houston, TX to get it and was pleased that it got 22mpg on the way back to TN by me keeping it under 70 most of the time. About 150 miles of that was in severe rain and wind in the left over effects of the storm that hit Oklahoma City.

I noticed that it does not lock into 6th gear until it gets to about 62 MPH. Will it be a problem to tow my 14,000 lb 5th wheel in 6th gear out on the open road, or do I need to keep it in 5th gear manually?
Thanks for your comments.
Tystevens
Explorer
May 14, 2013
Loved my '06 LBZ. Best vehicle I have ever owned -- that truck exceeded my expectations in every way. Well, except fuel mileage, where it merely "met" my expectations. 50k problem free miles, only sold it because our family outgrew it.

Mileage wasn't awesome, though -- 15 mpg commuting, 17.5 freeway speeds (75 mph or so), 19.5 on the back roads at 60 mph unloaded. Towing was between 10-12, depending on conditions (mostly whether we were going in to the wind or not).
DustyR
Explorer
May 14, 2013
I have a 2008 Chevrolet Silverado 2500HD Duramax and just completed a 1760 mile drive from Rio Hondo, TX (Winter Texan)here to my home in WV. I averaged for the trip (vehicle completed loaded, mostly bulk) 18.4 MPG. My driving speed was the speed limit plus 4 or 5 mph GPS. The fuel mileage remained the same from the 45 mph hi-ways up to the 80 mph roadways. The LMM series is where they loaded the vehicle with the DPF and converter, every time the DPF regenerates it drops my mileage by 2 mpg for the tank so the mpg suffers during short trip driving. The vehicle has 98K on the odometer and I may address the regeneration issues in the future.

Keep that pre-emission Duramax until it rots off of the frame. IMHO
bigbullelk
Explorer
May 14, 2013
I'm a recent convert. After much research, I settled on finding an 06 Duramax LBZ to replace my 07 Tundra. Tundra was great but didn't have the payload capacity.

I lucked out and found my LBZ with 25k miles on it about 2 months ago. All I can tell you is I am absolutely thrilled. I actually get better MPG with the LBZ than I did with the Tundra commuting in Atlanta traffic 50 miles each day. It is a CC 4x4, bone stock with exception of one size tire up (265) from stock (245).

Normal commuting week for me -- about 18.5 mpg. Highway -- 19.5. Towing -- 12-13 mpg. I drive like an old fart though.

In Tundra, the same MPG's were 16.5, 17.5, and 8-9 mpg respectively.
bigbullelk
Explorer
May 14, 2013
I'm a recent convert. After much research, I settled on finding an 06 Duramax LBZ to replace my 07 Tundra. Tundra was great but didn't have the payload capacity.

I lucked out and found my LBZ with 25k miles on it about 2 months ago. All I can tell you is I am absolutely thrilled. I actually get better MPG with the LBZ than I did with the Tundra commuting in Atlanta traffic 50 miles each day. It is a CC 4x4, bone stock with exception of one size tire up (265) from stock (245).

Normal commuting week for me -- about 18.5 mpg. Highway -- 19.5. I drive like an old fart though. Towing -- 12-13 mpg.

In Tundra, the same MPG's were 16.5, 17.5, and 8-9 mpg respectively.
Hamops
Explorer
May 09, 2013
I have an '06 LBZ Dmax and it runs like a top. It has all the power that is needed and with the 6 speed Allison, it's ideal for towing our 5vr that has an average weight of 10500 lbs. (11660 Gross) When I'm towing our 5vr, I turn on the Tow/Haul, set the cruise at 64/65 mph and let the computers do the work. With this set up, I average about 12 mpg. I can't complain about that. By the way, the engine is bone stock.