they limit the speed while towing to either 55 mph or
62 mph (100 km/h). This is really not suitable for highway use in the
Western United States.

Mere curiosity, what is the speed limit in the US highways? I was under
the
impression it was rather low.

Michel TALON

The "posted" speed limits in the Western US are 75m/h = 120km/h.
I may have seen 80m/h as well but I can not remember for sure.
The "normal" cruising speeds are about 85 - 90m/h ~ 140km.
In the Eastern parts of the US it ranges from 60 to 70m/h
This allows for a cruising speed of 70 to 80 m/h =115 to 128km/h.
Unlike Europe, specifically Germany, we are able to maintain a very good
average speed in North America. When visiting Germany I find
when driving on the Autobahn the average speed is lower
then one would expect. This deception is cause by the occasional burst
of that famous unlimited speed on the Autobahn.
One other interesting thing, that has not been mentioned, is the fact
we over here, Canada&US,have to "compete" directly with the large trucks
that have no problem diving at speeds of 120km/h. In Europe If I remember
correctly the trucks are limited to between 80 and 100km/h.

One other thing relating to more powerful tow vehicles.
A Gliding friend of my is very happy with his Jetta station wagon Turbo
Diesel
here in Canada. He says it is very comfortable towing a cobra trailer.
It is powerful enough and it has enough torque for a quick getup and go.
Regards
Udo