I was wondering what is holding the 6.0 back from the 12K lb towing of the 8.1 and max. The only differences are the engine and tranny, right? So is it a case that the tranny cant handle the extra 2k or is it that the 6.0 just doesnt have the power for it? I assume the brakes are the same for both trucks.

look at fifth wheel trailering, i believe the max goes well over 12k. i might be wrong. i traded an 02 6 for the max. best thing i ever did;) . i was towing a 10 k fifth wheel with it and pulling up grade was not fun-:t -:t -:t . let me see if IIrc second gear/ 4200 rpm/ 45 mph Censored . now same trailer/ same grade/ juice on level 2, 4th gear/ under 3 grand, and 60 mph:thankyou2 . to each his/her own. that kind of rpm cant be good over the long haul:eek: . oh by the way when i would pull those kind of grades with the 6, my tranny temp would be aproaching red line and temp also-:t -:t :damnit1: :banghead: . my opinion is biased, if you want to tow go trade in for a diesel.you wont regret it:blahblah:

Ok peekok...

You've met your quota of smilelys for this week!

noooo please dont take my smiley priveiledge away.:eek:

My 6.0L Vortec was a great little engine that could! On its own, it got good fuel mileage, the short bed crew cab was near perfect for off roading in 4X4, and the interior creature comforts were above expectation for a light truck....

....Towing a fiver was a different story though. The trailer seemed to do 1/2 the driving, expecially on the down slopes, the fuel mileage dropped down to 5.5 to 8 MPG (worse than with the previous 7.4L big block), and it would ..... slide .... through yellow-turning red lights with the trailer brakes locked up.

The heavy towing (roughly 10K) was taking its toll. Busted engine mounts, cooked tranny fluids, and 3 sets of rear wheel bearings within 55K miles, even with the HD tow package. traded it before it completely fell appart.

My 89 5.0L / 5-Speed could not keep up with the 6.0L on the climbs, but got 10 MPG and lasted 110K miles with the same trailer (but it had duallies). It was traded because it did not have A/C, and we had moved south (hot S.O.B. in summer time).

The 7.4 was another story! It could move mountains (but could not stop them) and tended to run HOT under any towing conditions, especially at low speeds, while maneuvering trailers into tight spots.

You can never have enough truck, but its easy to find yourself with a deficit when the road or weather is at less than optimum. Take it from someone that has chewed up a few seat cushion along the road to towing wisdom :driver: !

I'm not looking to see which is better; I know the duramax will out tow it. I just want to know why the max can handle 2k more. Can the 6.0 and tranny not handle that extra weight? Thanks

P.S. I'm looking at ballmount #'s

just my .02 but I have a 04 2500hd 6.0 ex cab sb 4x4, and I tow a 24' fiver roughly 7-7500lbs and it handles it pretty well but going up a 5-6% grade she has to work pretty hard, never had any tranny issues, that part is pretty good been towing on 85+ degree days in stop and go traffic and the temp stays at 200 or less.

gtchief,

I think the answer to your question is that the Dmax has more torque at a lower RPM and the allison is a stronger transmission than the 4L80E.

Will the 6.0 pull the same load everything else being equal? Yes, but it won't do it for long and GM doesn't want to change engines and tranny's every 10,000 miles.

The obvious differences are as you pointed out, the engine and transmission...and those are substantial differences.

The stock Allison 1000 is used in medium duty's with GCVWR's of up to 26K, far higher than the stock 4L80e. Secondly, as has been pointed out, the Duramax develops much more low end torque than the vortec 6000. They may both have a similar peak HP in the pickups, but if you look at an HP curve, the Duramax has a lot more HP at 1800-2200 RPMs. The superior low end torque gives the diesel this low end HP advantage. Sure you can rev the 6.0L gasser up to give the same HP (and thus the same towing speed), but you are causing much more wear and tear (and using a lot more fuel) to do so. The big block vortec 8100 has many of the same low end power advantages over the 6.0L and that's why it has similar tow ratings when paired with the 4.10 rear gears.