We just completed the maiden towing voyage of our latest tow rig: a 2018 Yukon Denali. We traveled from N. Texas to SW Colorado towing our XJ on an all-metal trailer. While I've never bothered to weigh it, I'm guessing the loaded trailer weights round 6,000 - 6,500 lbs.
According to the trip computer, we travelled 1,893.2 miles and averaged 11.7 miles per gallon while maintaining the speed limit or better pretty much constantly. We pulled over Raton and Monarch Passes as well as several lesser "summits" along US 50 with no trouble at all. We even passed a 3/4-ton pickup pulling a large travel trailer while going up Monarch Pass.
The 6.2L V8 (430 hp / 460 lb.-ft.) and ten-speed auto make for a great towing combination. Control and braking were also exemplary. My wife commented repeatedly that from the passenger seat, she could not tell we were towing at all. We were
very pleased with the results. It's quite an improvement over our 2007 Suburban (6.0L and four-speed auto). In fact, it was no comparison really.
Also, this was our first time towing while using a weight-distributing hitch and I can say quite confidently that I'll never tow another heavy load without one. It makes a huge difference! We chose the
Andersen Weight Distribution Kit that uses poly bushings instead of metal torsion springs, and I can't say enough good things about it. Highly recommended!