Terry asked:
<Why in the heck is this reinforced truck tire thing so important?>

In my experience, it improves handling in a huge way.  When I bought my van,
the PO had "car" tires on it.  The ride was sloppy, and a wind gust would
change lanes for you.  They just weren't that great.  When I switched to a
taller (correct sized) truck tire with 8 plys and reinforced sidewalls,  I
suddenly had a vehicle that held the road, and the steering got a lot
snappier.  Sports-van!  Actually, it's a lot safer on the highway and easier
to maneuver.  I also believe that vehicle weight is a factor, as well as
correct inflation pressures.
       Of course, the driver won't notice the increased safety involved with
correct load factors, but the snappier response is directly noticeable.
       That will be $.02, please.

Bill Marshall
85 GL Tiico
Phoenix AZ