I tow with my truck and the factory p265/70/17's are crap. They squirm all over the place. I then switched to LT285/70/17 BFG AT KO's Load Range D and it made a world of difference. The side walls are much stronger and made the trailer much more stable. They wore out and I'm wanting to go to a more sport look so I was going with the tried and true 275/55/20's but all I can find are P tires. Some are extra load (XL) so they may be a bit stiffer, but still aren't LT tires. I was hoping the much smaller side wall would give less flex, but who knows.

Has any one pulled a trailer with 275/55/20? How bad was the side wall squirm?

 

I pulled quite a few miles on the original 275/55 goodyears and they seemed ok (not sure on the rating) Tires suck as far as grip goes though imo.

Right now im running 265/50/20 grabber uhp's XL rating they seem ok but I havent done much highway pulling yet.

 

I had 275/55/20 on my last set of wheels they were Pirelli scorpion atr and I towed our pop up and the bed loaded down and never had a problem. The truck rode fine with the extra weight on the highway.

 

I pulled my 26' travel trailer from where I purchased it to my farm, about 250 miles, on275/55/20 Hankook Ventus RH06's and had no issues. They are V-speed rated so the sidewalls are pretty stiff. I pulled only on the receiver hitch; I didn't have a load-equalizing hitch or sway control bars.

 

when my truck was stock i had the stock goodyears and i towed quite a bit with them. Truck did great, i have a 32' travel trailer that dry weight is 7500lbs and it towed it great even in ice and snow. Fully loaded it was closer to the 9K mark and still did fine even with the quad in the bed. Although i did use a weight distribution hitch, but it did work amazing.

 

The SS's and VHO's came stock with 275/55-20's, and now a bunch of different models come optioned with that tire size, and these trucks all have towing capability...GM wouldn't option an unsafe wheel and tire combo on vehicles that can tow.

 

The truck was rated to tow 10k pounds from the factory with P rated tires. I don't know how because the side wall flex with the p tires is downright scary when you have a trailer behind you. When I switched to Load range D BF AT KO's the difference was night and day.

 

I tow an eighteen foot, 6,000 lb. car trailer without issue other than the 5.3 engine lacking some omph.

The tires on factory 18" x 8" rims are:
Currently - Bridgestone Dueler H/T D684 II, 265/65R18
Previous - Bridgestone Dueler A/T RH-S, 265/65R18

The 2007 Avalanche has Hotchkis brand anti-sway bars, Air-Lift brand air bags and Bilstein shocks/struts.