Thanks For posting the owners' manual stuff for the Highlander. I was actually hoping that they don't publish Gross Combined Weight Rating anymore, because it fits with the other things Toyota is telling us.
Most car and light truck manufacturers have been providing a rated tow capacity which for some reason includes the payload capacity of the tow vehicle (I'm thinking this is a little deceptive, actually). The effect is to follow a formula that works out like this:
Max Tow weight = Gross combined weight rating, minus the actual weight of the loaded tow vehicle.
(in other words, every ounce in your tow vehicle subtracts from your tow rating)
Because of this,
the actual towing capacity of most vehicles is actually much less than the rated towing capacity. Further, the tongue weight is an afterthought and the axle weights do not receive any attention.
Toyota, on the other hand is stating it much differently, so that the rated towing capacity is still pretty much there for you with a fully loaded tow vehicle. I don't know all cases or even most cases, but this is a pattern in the Toyota cases we've been discussing in this forum.
Today, Toyota defines their towing rules with clarity and detail:
http://www.toyota.com/pdfs/towguide_Part1.pdf
http://www.toyota.com/pdfs/towguide_Part2.pdf
http://www.toyota.com/pdfs/towguide_Part3.pdf
There are different kinds of equipment with associated capacities that can vary widely within a tow vehicle family (for example the max tow capacity for a pickup is likely to be with a fifth wheel hitch). There are specific constraints that always apply (tire loads, hitch loads, speeds, surface area of the front of the towed vehicle, etc). The Toyota towing guide also has a lot a lot of good and useful information for everybody about towing.
But, from Toyota, the bottom line in these documents is to not exceed the rated tow capacities and the axle weights. In these documents GCWR is defined, but never used (if I've missed it somewhere, please let me know).
Toyota is saying that if you don't exceed your axle, tire, hitch, tongue, etc. limits, you can tow your rated tow capacity, period. No formulas where you have to subtract the weight of the dog and the spouse from the tow rating appear to exist in Toyota owners manuals or towing instructions.
If there's a late model Toyota owner out there whose owners' manual says otherwise please tell us what it says, because we'd all like to know (but let's get to the real towing instructions, not just the sales brochure, the specifications table or some warning note out of context).