Thank you for your reply. I actually thought that the suburban and the Yukon XL were, technically, the same car with a different label. The Yukon XL seems to have about the same wheelbase as the Suburban. Am I right or is the Suburban a different truck then the Yukon? Neither truck seems to have a short wheelbase.
What was the tongue weight of your trailer?
From your reply I understand that power to get up an incline is not the main concern with a (1500) Suburban or Yukon XL with a trailer with an actual weight of 6.000 lbs. The real concern is being in control. Is your advice therefor to start looking for a 2500 Suburban of Yukon?
I missed the XL. Yes the Suburban and the XL are basically the same. So wheelbase should be okay.
Both the Suburban and Yukon XL 2008 and later can be found 3/4 ton, 6.0L, 6-Speed Auto; most have 3.73 some have 4.10. The 2007 3/4 ton Suburban came with a 6.0 and 4-speed Auto. The rated towing capacity is higher with the 6-speed auto. Last year of the 8.1L was 2006.
I think the Denali is only 1/2 ton but I could be wrong, but I think the Denali comes with the 6.2L.
Another thing you have to consider is the weight of the vehicle itself. A 1/2 ton Suburban is heavier than 1/2 ton Tahoe and much heavier than 1/2 ton extended cab pick up. So the 1/2 ton pick up can typically handle a trailer of your size better than a 1/2 ton Suburban or Tahoe, it has more power to spare and less weight on the suspension.
My tongue weight varies depending on how full the tanks are. 50Gal water tank is in front of the axles, 40Gal gray and black tanks are behind the axles. Beginning of the trip my tongue is heavier, typically around 900lbs. End of the trip typically around 600 (I have to shift some of my load forward on the return trip). Use the typical recommendations with the tongue weight somewhere between 10 and 15% of the total weight of the trailer.
I have an Eaz Lift hitch and had to use 1400lb spring bars to try and level the Yukon after hooking up. I ended up with a lot of weight on both front and rear suspension of the Denali and the whole truck front and back being lower by 1.5 to 2 inches after getting everything level. I could have gone to air bags or something else, but in the end I knew I was fighting a losing battle. When I hooked up the trailer to the Denali the tongue weight maxed out the carrying capacity of the Denali and put any more gear in the Denali and could not any passengers other than my wife. I have a friction sway control as well, and even then those side wind gusts pushed me around quite a bit, as well as the Semi-Truck trailers passing me. When I hooked up the trailer to my 3/4 ton Suburban there was hardly any deflection in the rear, about 1.5 inches without spring bars. I found that the 1400lb bars are way too strong with the 3/4 ton (driving the 210 freeway near Pasadena, beat the living cr@p out of me). I have picked up some 1000lb spring bars and will try them on my next trip. If they are too strong I'll try 750lb bars.
So lots of choices. In the end I wanted something with strong suspension and better braking ability than a 1/2 ton. I also needed passenger capacity so that left out pick ups which meant leaving out diesel as a choice.
Regarding pulling up a grade with a Suburban, you will probably have more towing capability in a later model 3/4 ton with a 6-speed auto than a 1/2 ton with a 4-speed auto. I only use my Suburban for towing and Saturdays to car pool a bunch of athletes around, it is not my daily driver; so going with a used low mileage 8.1L 4-speed auto works for me.
My recommendation is to look at a 3/4 ton. I think trailer weight wise, with a 1/2 ton you are at the hairy edge of having enough control when you need it most. The 1/2 ton has a much nicer ride than a 3/4 ton, but I can live with that issue.