Chevrolet 2011 Volt Owner's Manual page 427

GM recommends that the
tires, including the spare, be
inspected for signs of wear or
damage at least once a month.
Replace the tire if:
The indicators at three or
more places around the tire
can be seen.
There is cord or fabric
showing through the tire's
rubber.
The tread or sidewall is
cracked, cut, or snagged
deep enough to show cord
or fabric.
The tire has a bump, bulge,
or split.
The tire has a puncture, cut,
or other damage that cannot
be repaired well because of
the size or location of the
damage.
Tires should be rotated every
12 000 km (7,500 mi). The first
rotation is the most important.
See
.
Tires are rotated to achieve a
more uniform wear for all tires.
Any time unusual wear is
noticed, rotate the tires as
soon as possible, and
check the wheel alignment.
See
and
Use this rotation pattern when
rotating the tires.
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
.
.