Hi All. I have a 2018 Discovery Td6 with the optional class IV tow hitch which is rated to tow 7700 lbs and thought I would share my experience in case it is helpful to someone. For about a year I towed an Airstream Nest travel trailer over thousands of miles through all kinds of road and weather conditions and for that 4000lb trailer the D5 was the prefect tow vehicle. I did not use any sway control or weight distribution and was able to tow at speeds up to 75mph safely and comfortably. Plus, when I arrived at a destination I had all the off-road capabilities of the Discovery to get me to trailheads anywhere I wanted to go. It was really a great setup.
About a year ago we traded the Nest for a 2020 Globetrotter 23FB which is about 6000 lbs. Those extra 2000 lbs completely changed the dynamics of towing. This setup absolutely requires sway control. I towed the Globetrotter for short distances with out, and that is not a good experience at any speed above 50 mph. I really wanted to use a weight distribution hitch with integrated sway control, but after doing a lot of research and speaking with a couple guys at Caman RV I decided to go with Land Rover’s recommendation to not use weight distribution. If you look up a drawing of the D5 trailer hitch (
https://www.landroverpartscounter.com/oem-parts/land-rover-kit-tow-bracke-lr083050) it is more or less a straight bar without the long extensions on the sides that most hitches have to handle the torque applied to the hitch with weight distribution. My conclusion was that the torque from a weight distribution setup would just be too much for the short side arms on the D5 hitch and I was not comfortable with this.
My solution was to install a Tuson Electric Sway Control on the trailer along with a Curt Friction Sway Control. With this setup we have been able to safely tow our Globetrotter through difficult conditions such as high winds, rain and mountain passes. In high winds it is noticeable, and extremely impressive, to feel how the Tuson activates the trailer brakes to control sway. One thing to note for Airstream owners is that Airstream brakes are wired in series which, at least for me, made this not a do-it-yourself installation. My local Airstream dealer charged about $500 for installation which was well worth the price.
Having said this, I am still not happy with the experience of towing a 6000 lb trailer with the D5. While this setup does a good job of controlling side-to-side sway, it does not prevent the up-and-down motion of the back end the vehicle over rough roads. Towing over the undulating pavement of rural Colorado roads for a few hours felt like piloting a small boat over rough seas and made me sea-sick for the first time in my life.
I know there are many comments that Land Rovers do not require weight distribution because of the auto-leveling air suspension. It is true that the auto-leveling does an amazing job of keeping the vehicle level regardless of how much weight is put on the rear end of the vehicle. What is cannot do, however, is distribute some of the hitch weight of the trailer from the rear axle to the front axle, leaving the rear axle to act as a pivot point. This, I believe, is what results in the up-and-down motion that is felt over rough roads.
Finally, the diesel engine in the Td6 is outstanding for towing. I’ve pulled the 6000 lb trailer up steep grades over high elevation mountain passes at highway speeds and the Td6 never struggled at all. The fuel economy of the diesel is also impressive when towing, averaging about 17-18 mpg.
My advice is that if you are towing a trailer weighting around 4000 lbs the D5 Td6 is a great tow vehicle, but if you are getting much above that the inability to use weight distribution becomes a limiting factor. We have decided that for our 6000 lb Airstream it is time to look for something with a higher tow rating that allows the use of weight distribution.