On Mon, 4 Aug 2008 13:05:48 -0700 (PDT), "
wrote:

The other alternative is to get a full size truck such as GMC Sierra
or Nissan Titan. According to Nissan Titan owner manual, it doesn't
have this 45 MPH restriction, and the "sway control device" is an
optional "nice to have" item. But I am afraid that it is an overkill
for my 3,000 pounds boat/trailer combo, and its fuel economy will be
worse than what I have now.

Any idea about that 45 MPH limit of Highlander? Is a Nissan PathFinder
a better choice

Simple answer - yes, you can tow your rig with a Highlander.

Sway bars are a nice addition to any vehicle that will do any towing
at all. You have to remember that it's not so much the weight, but
the environment you are towing through. Heavy rain, wind, etc., all
affect towing and the sway bar will help control the load. Even
highways have problems with crown and pitch and the sway bar will help
in manuevering at relatively high speeds. They aren't necessary by
any means, but they are a big help.

With respect to speeds, 45 mph is a little extreme in the caution
department. I tow just under 5,000 pounds and will not go over 60 mph
under any circumstances. I stay around 2200 rpm and 60 mph with
overdrive off. Depending on terrain, those figures will change - rpm
up and mph down, but on average, 2200 and 60 seems to work just fine.

Any new rig with a tow package will work as well - I would opt for the
sway bar (as I did with the F-150) just to be that much more cautious
in varying driving conditions.

Good luck.