I need to buy a new car to replace my PathFinder (it is too old). I am
considering many difference choices. The top one on my short list is
2008 Toyota Highlander. This new model can tow 5,000 pounds. More
importantly it has great fuel efficiency (17 City / 24 Hwy). However,
according to the owner manual PDF file available online, this car
should only drive no more than 45 MPH if it is towing thing. The owner
manual doesn't say if it is applicable to a certain towing weight or
above. Seem like it is across the board regardless how much towing
weight involved. This makes me worry because 45 MPH is too slow a
driving speed on a highway. I am hoping to be at least 50 or 55 MPH.

I believe this restriction may have something to do with avoiding
swaying. According to the owner manual of my old PathFinder, it
recommends to use "sway control device" if I use it to tow anything
over 2,000 pounds. The total weight of my boat and trailer is close to
3,000 pounds. I am wondering may be the same recommendation is also
applicable for Toyota Highlander: Can I drive above 45 MPH with
Highlander if I equip it with anti-sway bar? Please note that
Highlander owner manual doesn't suggest or recommend the user of sway
control device; it is sounding like "Don't go above 45 MPH when
towing, period."

Is this 45 MPH limit a definite thing? Or is it more like a lawyer
talk?

There are several posts in the net from Highlander owners saying that
they didn't have any problem towing at 60 MPH. There was trailerboat
magazine article did road test on Highlander in towing a 4,020 pounds
boat/trailer combo, and it didn't say anything about the 45 MPH limit
or any swaying problem during towing; actually the author was driving
it at 55 MPH with a boat behind it; the only negative thing that the
author expressed had to do with towing the boat up a steepest hill at
55 MPH requiring the engine to spin at 4000 rpm (the heavy 4,020
pounds may have something to do with this). The article didn't say
anything about sway control device either. Doesn't sound like negative
real world towing experience to me.

I am confused.

The other alternative is to get a new PathFinder and add the
recommended "sway control device". Then, I am not better off or worse
off than what I have now.

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?

Thanks in advance for any suggestion.

Jay Chan