Ford 1998 Windstar Owner's Manual page 294

Improperly inflated tires can affect vehicle handling and
can fail suddenly, possibly resulting in loss of vehicle
control.
Tire Rotation
Because your vehicle's front and rear tires perform different
jobs, they often wear differently. To make sure your tires wear
evenly and last longer, rotate them as indicated in the following
diagram.
Rotating the tires
If your vehicle has the optional full-size spare tire, you may
rotate the spare tire into the rotation pattern.
If your vehicle has aluminum wheels, you may remove the
full-size (if equipped) spare tire from the wheel and remount it
on an aluminum wheel to rotate the spare tire into your
vehicle's rotation pattern.
Maintenance and Care
RWARNING
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