Check out this thread titled "Towing Questions". It was originally from 2011. But when I posted a question to the OP last a few weeks ago he explained the "rest of the story". The bottom line is that he is pulling an 27' Airstream Eddie Bauer with a tongue weight of 885 lbs and total dry weight of 5,900 lbs with a Hensley Arrow. Heavier, longer trailer than the Rockwood Roo 23IKSS. Though he is not using the OEM receiver. He had a Curt receiver permanently mounted to the frame by CanAm in Canada. I am using the bolt on Curt but its tongue weight rating is only 600 lbs w/o a WDH hitch and 800 with a WDH hitch.
Here is what DonFromCanada said in his post:
"Long story short. Don't exceed 550lbs on the tongue. Unless you want to get creative...
We went to a towing specialist who had done a lot of work with Range Rovers, Land Rovers, etc.
They installed a permanent Curt hitch and did some reinforcing of the hitch and rear of the truck to support it.
I had to remove the full size spare and go with the donut type to make room for this mod.
We run a Hensley Arrow load balancing hitch and a completely different rig than we originally thought. Also a Hensley Tru Gold brake controller.
Trailer is an Airstream Eddie Bauer 27' rated at 885 lbs on the hitch and dry total weight of 5900lbs and carrying capacity of 1800 lbs
When we did a weigh in the total trailer weight loaded was ~7150 and we calculated the hitch weight to be around 1050-1100 lbs
Tows great. Never had any issues. We get the trailer axles serviced every year. Brakes are due next spring.
Also run a tpms system on each trailer tire. Keeps your mileage good and if there's a blowout you'll have some warning hopefully before any expensive damage is done to your trailer."
When I PM'd DonFromCanada about the use of sway control and the receiver questions his answer was:
"I leave the sway control alone. Never have had any issues, but I usually drive slowly (never faster than 55).
The 550/700 thing is a weird Land Rover thing... The receiver can only handle 550. It's a limit of that stupid 500$ cast piece that fits into the bumper. The 700lb is what the draw bar can handle. So u have to listen to the lower number.
Air suspension has nothing to do with it. The Mercedes GL, and Porsche Cayenne all have the same rating. It has something to do with EU regulations on weights of towed trailers without a commercial licence. In Europe it's limited to 3500kg (or exactly 7716lbs)
If you do your research, you'll see all the biggest European SUVs have the exact same max tow load rating.. Meaning that they meet the max allowable in Europe. In NA, we can tow much heavier loads without a commercial licence, so our pickup trucks and SUVs are tested to their limit.
When I was at Can-Am, I tested a lot of trailers that they had set up there to demo their stability. I towed a trailer that weighed 11200 lbs with 1300 on the tongue no problem."