BG wrote on 12/17/2019 9:54 PM:
On Monday, December 16, 2019 at 12:03:02 PM UTC-8, princiar wrote:
Anyone has experience towing a trailer with a car with the trailer sway
mitigation installed?

I used to tow a DG 800 with a single axle trailer with a 4 Runner and found it
got to be quite a adventure. Any rapid turning would end up with a sway side
to side. I now tow with a Range Rover with 20" wheels with low profile tires.
The difference is night and day. IT was easy to understand the the major
difference is the tires. The 4 Runner had a high profile tire that flexed if
you pushed side to side on the rear of the car. The low profile tires have
virtually no sidewall flex. The suspension in the 4 runner was solid with
great sway bars, they however could not over come the flexing in the tire
sidewalls. In the Rover I can easily go any speed I desire with zero sway and
can change lanes at will. Push your car sideways at the rear and observe what
you see. Any motion will reveal why you have sway. I have seen many work
arounds with friction tuning to dampen sway, but none work better than
addressing the root cause.

The tire stiffness that is important is the lateral tread stiffness - how much the
tread deflects under side load. For this reason, radial tires are better than bias
ply tires, even though the bias ply tire might feel "stiffer" in your hand push
test. There are things that tend to increase tread stiffness and "side push
stiffness" at the same time, such as lower profile tires or higher pressure, so
it's easy to mistake what causes the improvement, and what is by-product of the
change.

There are likely other differences between the 4 Runner and Range Rover that make
one tow better than others, such as wheel base and hitch to rear axle distance. IT
would be fun to do the stability test with the same profile tire on vehicle. I
know at least one pilot that improved the stability of his towing by putting low
profile tires on the glider trailer, which is cheap and easy - worth trying if the
other factors (tongue weight, tire pressure, etc) don't help enough.

--
Eric Greenwell - Washington State, USA (change ".netto" to ".us" to email me)
- "A Guide to Self-Launching Sailplane Operation"
https://sites.google.com/site/motorg...ad-the-guide-1