Definitely thinking hard about it plus the resale is insane there are used dmax's going for the same money I can get this one new.

 

dmax if your going to be pullin alot

 

Are you going to be towing this 8000 pound trailer often? Or is this just a one time thing? It's not that the 1/2 ton truck CAN'T do it, but it's gonna suck in the mountains. Might even kill the rear diff, or the transmission doing it. I've seen plenty of Alcan Hwy travelers kill theirs over the years. "My salesman told me the truck could handle it....."

Okie Dokie. Here's your repair estimate sir.

 

Yea if its gonna be a monthly trip or something often, the dmax would surely be better.
But its all up to you.
A halfton frame doesnt like alot of heavy towing. Dunno how diff our frames are, but my 2000 is starting to show. Hook a heavy traiker to it and it bends the frame enough that the cab/bed gap gets considerably larger that i can place my forearm in the slot.

If you stay with the halfton, big brakes all the way around, hydroboost, helper bags, sway bar, and the largest transmission cooler you can fit. Throw in a custom tune also.

On the dmax it will handle the 8k load with easy. Throw on a turbo back and a tune and you have alot more tq to play with. Our 07 classic dmax work truck got roughly 9-14 pullin a 8500# 16' vanbody all over the country and it was bone stock.

Good luck on your deccision.

 

It's gonna be a annual trip out there not all the time. I live in the Midwest flat as can be here. If I have to keep my fingers crosses the whole time I'm out there its not worth it to me. Im a Gm tech so fixing it if it breaks is not a issue just after working on cars all week I hate working on my own.

 

I would think 18+ empty and 10-15 towing depending on terrain and your right foot.

 

My 06lbz got 12 pulling our 20' enclosed trailer weighing in around 12k through the mountains of new Mexico and Colorado while running 70-75 on 35" mt tires. All I had was a turboback exhaust and Efi tune. I didn't think that was too bad at all.

I've now got an 07 Vmax that I'm prepping to tow heavy. I just couldn't justify the price again for a diesel since I rarely tow more than 6-8k. I got the Vmax because I specifically wanted the bigger 14 bolt and 6.0 to handle towing duty better.

I think with 3k or so you could make it a towing machine.

 

When you get that 5.3L to Co's avg 6500' elv you will hate it. You're going to have ~230 hp and 250lbs of tq to work with. When you hit 10,000' that will turn into 165hp and 185 lbs. This is no joke. Combine that power with 6~8% grades, along with stiff cross and head winds it will be total junk. The duramax will maintain factory rated power up to 5-6000' and still have over 500lbs at 10,000'. You make the choice lol...

 

Keep in mind, that you cannot "custom tune" an LML (Last I checked, H&S was the only "good" option). HPT and EFILive do NOT, and will NOT support it. Also, kiss your warranty goodbye if you ever flash the truck with a non stock tune. Once you flash it, it is permanently stored in the ECM, that a non stock cal was written. Its a whole new ball of wax with the 2011+ Duramax trucks. This is a HUGE reason why I got a half ton gasser...I didn't want a "stock" Duramax w/ DPF and urea.

 

I bet 165hp doesnt tow to well