Chevrolet 2008 Optra Owner's Manual page 263

The purpose of a regular tire rotation is to achieve
a uniform wear for all tires on the vehicle. This
will ensure that your vehicle continues to perform
most like it did when the tires were new.
Any time you notice unusual wear, rotate your
tires as soon as possible and check wheel
alignment. Also check for damaged tires or wheels.
See When It Is Time for New Tires on page 5-62
and Wheel Replacement on page 5-66 for
more information.
When rotating your tires, always use the correct
rotation pattern shown here.
Do not include the compact spare tire in the tire
rotation.
After the tires have been rotated, adjust the front
and rear inflation pressures as shown on the
tire and loading information label. See Loading
Your Vehicle on page 4-18 for an example of the
tire and loading information label and where it
is located on your vehicle. Make certain that
all wheel nuts are properly tightened. See "Wheel
Nut Torque" under Capacities and Specifications
on page 5-94.
CAUTION:
{
Rust or dirt on a wheel, or on the parts to
which it is fastened, can make wheel nuts
become loose after time. The wheel could
come off and cause an accident. When
you change a wheel, remove any rust or
dirt from places where the wheel attaches
to the vehicle. In an emergency, you can
use a cloth or a paper towel to do this;
but be sure to use a scraper or wire brush
later, if needed, to get all the rust or dirt
off. See Changing a Flat Tire on page 5-69.
5-61