I was just reading this thread and was wondering what the enchantment is (besides novelty) with a 3500 sub. I've been towing for a long time, primarily enclosed trailers loaded with a race car, spares and tools, sometimes tipping 7000-8000lbs. While the diesel trucks are the best with 3/4 ton suspension and 900lbs of TQ, I found my Escalade ESV with an LT6.2 engine can handle the job fine....less a few MPGs. I think tow rating for the ESV is rated the same (8300lbs) as the 3500 Sub but the LT6.2 engines have a boatload more TQ than the 6.0L....460lbs vs. 380lbs.....it’s a big difference. And it’s TQ that pulls weight. I got rid of my diesel trucks, because the cost to maintain is so much more than the gassers. So I like 6.2s, DOD deleted! Have 2 LOL. And ESV's are so cheap, sub $20K tow vehicle....and comfortable with a rockin sound system. That being said, if GM made a 2500 Sub with a 6.6 L8T, I'd buy one Today! LOL
I’m with you on the L8T, and that 1500 rigs with the 6.2 can pull.
All the same, I towed our 7500 lb 32’ alpha wolf camper for years with our 2012 Yukon XL Denali and had to make several mods to keep temps cool towing in the mountains in the summer, and to tolerate the extra abuse (bigger transmission cooler, 700w cooling fan motor, thicker radiator, billet torque converter, etc). I also deleted the AFM to give me peace of mind - one less thing to fail and the bigger cam I put in made the 6.2 even more of a towing beast.
Alas, 5 years of towing have taken their toll on the rear air shocks (new when I started towing) and compressor. Had to replace the compressor in 2024 and I’m chasing a new slow leak somewhere in the system. And I was always running right at the payload limit and sometimes over it with 2 kids + 1 friend each on many trips, and a 100lb dog.
But despite being down a bit on power, the Suburban 3500 hauled it better, thanks to the 4.10 gears. Now we have an Airstream that’s 500 lbs lighter overall but puts an extra 300 lbs on the tongue, and the Suburban 3500 couldn’t care less. Still have 2600+ lb payload margin, fully loaded. And the 3500 is more stable in high winds. No problems with engine or transmission temps either - even in the mountains. And the 3500’s brakes are significantly better.
Lastly, the 6L90 is a stouter transmission and the 14-bolt full floater is nigh unbreakable. I fully expect to be able to put 200K towing miles on this rig. I’d have to put a rear end, a torque converter, a transmission, and 3 sets of air shocks plus compressors on our XL Denali in that time.
