We’re taking our 2018 Acadia Denali on its first camping trip this Friday. It’s identical to yours, 3.6 V6, V92 tow package and 4000 lb rating. Our trailer is 3100 dry. I’ll update this thread. Using a Curt Echo - though there are blunt cut wires by the gas pedal, right behind the plastic panel if you want to wire a brake controller.
From all the measurements I’ve done we should be safe on payload, GCWR, GVWR. I’m going to tow it with empty water tank for extra margin.
This exact same engine and transmission are rated for 5000 lbs on the Traverse and Enclave, which are slightly longer versions of the Acadia chassis. I feel confident the drivetrain is more than capable of handling 4000 lbs. it’s the chassis that is a question.
I’m planning on using a WDH.