I wondered what was so different from my 06 LBZ and the 2012, since the tow guide on the Chevy web site says 23,000lbs towing now and my old 06 says 18,600 lbs, with the same eng, trans, and gear ratio.

I see the new truck has 2 1/2" reciever changed up from the 2".
The wheels and tires are larger for higher rating. Also the hub bolt pattern changed in 2011 to the larger heavier rating. My O.E. tire size is 30" and the new tires size is slightly over 31". Did any gearing change in the trans for this?????????
The spring mounts on the rear axle is now cast on the new truck where the 06 is still stamped steel.
The trans cooler mounted under the cab/bed is not there on the new truck. Why is that?????????

These are some things that I noticed looking around the truck.
What all else is different pertaining to the 23,000lbs tow rating??????

GM must have done more to it to get that extra 4400lbs.Either that or you're looking at the gooseneck rating...

6 speed tranny?

Of course GM made changes. I listed some that I saw with my own eye in a direct comparison. Did you read my first post? These are some obvious things that are on the surface and I want too know what else has changed? Like: have any gears changed in the trans ratios? Something like that does not meet the eye.
Are you saying more changes than what I saw?

Yes. Both trucks have 6 speed Allison trans but since the tires are larger, for heavier rating, the trans ratios must have changed. With 3:73 gears and same Eng and trans my 06 is miserably under rated or something more changed. That is what puzzles me.

Yea the Eng is tuned up more on the 2012 to 395hp and 750tq over my 360hp and 650tq but I kind of expected more than what I saw on the surface would be needed for the extra rating.

Oh well. It could be that GM is sand bagging as always and not showing their full hand; more power than they tell.

365/797 slight gear changes in the tranny getting power to the ground better. Much stiffer frame and use of different metals....revised front and rear suspension calibrations...better exhaust brake, larger discs, slightly taller tires...and a few more things I can't think of right now.... the only thing that I can tell you that has not changed is GM's sad excuse for an interior.

I like the 07 up interior better than my 06. The seats especially are a home run. Those new seats are perfectly comfortable. MY old style seats suck and I'm looking for a method to change my style for the new style.

I seems GM could do better proportions for the interior but it is not as bad as some.


Which trans gears had ratio changes?
The tire size changed by over 1" which makes me think the ratio's must have changed.

Looking at 2012 GMC vs. Dodge/Ram. Does anyone have some real world comparison on towing and everyday drive-ability? Looks like bumper pull w/ 3.73 ratio gets you around 13K towing, seems a little light or borderline (SRW). Is anyone running the taller rear end w/ 4.11s or 4.10s?

Personally I think the Dodge is pretty hideous, as usual, but I've heard pretty good things about the package.

23k is the gooseneck rating but, in 2011 GM finally installed a rear hitch with non-weight distributing rating of 13k (closer to what people actually use it for). Prior, non-weight distributing was only 7500#/750 tongue, which is a joke for a HD.
GM still did not go as far in communicating proper loads as Ford did, where they actually specify on the hitch not only the WD / nonWD values but also derated values if the 2" adapter sleve is used.
What really pisses a guy off is when he can bolt on a 2" Curt rated to 17k at the bumper for less than $200 shipped. That means GM is handicaping an owner of a $40-70k truck and skimping on less than $25 steel.
The bigger problem becomes finding a ball mount / ball that are rated for more than 7.5k-12k. Walmart or many trailer stores dont stock things that heavy (read - expensive)

Like Jassman, The big bump in max load came with the new frame and front end in 2011. The internals of both the Dmax and Allison also received some improvements but only the Allison changes would be directly tow related.
GM also increased the GVWR over 9900 to acheive these higher ratings which caused tagging/tax heart burn in some states.

For almost direct comparison, I traded my 06 LBZ on a new 2012 Dmax about two months back.

Not quite apples to apples, the LBZ was 2WD 2500HD SRW, where the 2012 is 4WD 3500HD SRW.

Both fully loaded with all the bells and whistles. Apart from the obvious 2500 to 3500 difference, the 2012 is still more truck like. Sounds obvious of course but it comes across as more than just going to a one ton.

If I did it again I would have done GMC Denali with the same package to get the nicer interior. Didn't due to end of month incentives and dealership needing to move floorplan etc and getting a stupid low price ($54k out the door all included). IMO the 2012 interior Chevy LTZ isn't as nice as the 06 fully loaded interior, excepting the 2012 AC cooled seats and dash navigation. But that just personal preference.

For gear ratio info, I upgraded to 305/55/20 Falken WildPeak and KMC wheels that still have plenty of load rating for what I do and didn't lose much payload at all. With the taller tires and levelling kit in the front it still has more "seat of the pants dyno" towing power than the 06 LBZ. So I wouldn't worry much about the trans ratios when comparing the two.

The exhaust brake on the 2012 is a big upgrade over the 06.

All in all, it was a good swap if that helps you. Truck is a beast.