wtxnitz -
I did not know the meaning of "GSU55L-ARTGKA", so I googled it. One of the hits was
http://www.toyota.com/t3Portal/document/om/OM48A12U/pdf/sec_04-01.pdf
This is apparently part of a Toyota manual (Owner's Manual?) for the Highlander. This is one of the best pieces of documentation I have ever seen, and I admire Toyota for it. Lots of info, easy to understand. One thing caught my eye. On page 209 I find
TWR (Trailer Weight Rating)
The maximum allowable gross trailer weight. The gross trailer weight is the sum of the trailer weight and the weight of the cargo in the trailer.
. TWR is calculated assuming base vehicle with one driver, one front passenger, towing package (if available), hitch and hitch systems (if required).
. Additional optional equipment, passengers and cargo in the vehicle will reduce the trailer weight rating so as not to exceed GCWR, GVWR and GAWR.
The terms GCWR, GVWR, and GAWR are also clearly explained.
In other words, allowable trailer weight assumes a set of base conditions in the tow vehicle (one driver, one passenger, hitch and hitch system, no cargo). If you add more passengers, or some cargo to the tow vehicle, then you must reduce the trailer weight rating,
but only until you bring the GCWR, GVWR, and GAWR back within spec. This is different from other manufactuers' statements, in which you must reduce trailer weight rating ing pound-for-pound for the entire weight of extra passengers and cargo in the tow vehilce.
This has not been my understanding in the past, so I stand corrected. It has also not been the expressed opinion of members who have maintained that NO reduction in trailer weight is required.
Another note of interest is on page 214, where it says that if you use a WDH, you should adjust it to return the front end to the same weight and height as before. No mention of air bags or helper springs.
We learn something every day on this forum. Thanks for your post!
Bill