Saturn 2009 ASTRA - Manual (Page 239)

GM’s exclusive TPC Spec system
considers over a dozen critical
specifications that impact the overall
performance of your vehicle,
including brake system performance,
ride and handling, traction control,
and tire pressure monitoring
performance. GM’s TPC Spec
number is molded onto the tire’s
sidewall near the tire size. If the tires
have an all-season tread design,
the TPC Spec number will be
followed by an MS for mud and
snow. See Tire Sidewall Labeling on
page 9-42 for additional information.
GM recommends replacing tires
in sets of four. This is because
uniform tread depth on all tires will
help keep your vehicle performing
most like it did when the tires
were new. Replacing less than a
full set of tires can affect the braking
and handling performance of your
vehicle. See Tire Inspection
and Rotation on page 9-52 for
information on proper tire rotation.
{ CAUTION
Mixing tires could cause you
to lose control while driving.
If you mix tires of different
sizes, brands, or types
(radial and bias-belted tires),
the vehicle may not handle
properly, and you could have
a crash. Using tires of different
sizes, brands, or types may
also cause damage to the
vehicle. Be sure to use the
correct size, brand, and type
of tires on all wheels. It is all
right to drive with the compact
spare temporarily, as it was
developed for use on the
vehicle. See Compact Spare
Tire on page 9-68.
{ CAUTION
If you use bias-ply tires on
the vehicle, the wheel rim
flanges could develop cracks
after many miles of driving.
A tire and/or wheel could fail
suddenly, causing a crash.
Use only radial-ply tires with
the wheels on the vehicle.
If you must replace your vehicle’s
tires with those that do not have
a TPC Spec number, make
sure they are the same size,
load range, speed rating, and
construction type (radial and
bias-belted tires) as your vehicle’s
original tires.
Vehicle Service and Care 9-55