Yep, winter is 3rd gear as I understand it.  Never have used it - designed
for very slick roads and getting started.  Kinda like I once did with the
old 79 Ford van, you could put it in 2nd and it would lock into 2nd.  Unlike
the new vehicles that 2nd gear still starts in 1st.  That trick saved me
from being stuck more than once.

You're right on the "power" button.  Turn it on while you're driving and
you'll see the difference.  It will hold gears a little longer before
upshifting.  I found it didn't do much for our 94, even when towing an 18'
travel trailer.

However, our 2002 has the same button that makes a world of difference.  By
default it likes to grab the next gear too quickly for my liking, and then
doesn't want to back down a gear when you need it.  With the power button
on, it holds gears nicely (almost too long though) and will back up a gear
pretty quickly when needed.  I read somewhere that it supposedly makes some
change in the pressure of the system...sounded like it would be bettery for
the tranny too.  At any rate, I just leave it on all the time in the 2002.

Wesley