Buick LaCrosse Owner's Manual page 399

Tires should be rotated every
12 000 km (7,500 mi). See
.
Tires are rotated to achieve a
uniform wear for all tires. The
first rotation is the most
important.
Any time unusual wear is
noticed, rotate the tires as soon
as possible and check the wheel
alignment. Also check for
damaged tires or wheels. See
and
Use this rotation pattern when
rotating the tires.
Do not include the compact
spare tire in the tire rotation.
.
Adjust the front and rear tires to
the recommended inflation
pressure on the Tire and
Loading Information label after
the tires have been rotated. See
and
.
Reset the Tire Pressure Monitor
System. See
.