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Black plate (37,1)Chevrolet SS Sedan Owner Manual (GMNA-Localizing-U.S.-7707491) - 2015 -
crc - 9/16/14
Vehicle Care 10-37
Caution (Continued)
damage. Keep tires set to the
correct inflation pressure and
when possible, avoid contact with
curbs, potholes, and other road
hazards.
Summer Tires
Ultra High Performance Summer
Tires
This vehicle may come with 245/
40R19 and 275/35R19 ultra high
performance summer tires. These
tires have a special tread and
compound that are optimized for
maximum dry and wet road
performance. This special tread and
compound will have decreased
performance in cold climates, and
on ice and snow. Driving a vehicle
with ultra high performance summer
tires when temperatures are below
approximately 5°C (40°F) is not
recommended. If driving in theseconditions, winter tires should be
installed. See
Winter Tires on
page 10-36.
{Caution
Ultra high performance summer
tires have rubber compounds that
lose flexibility and may develop
surface cracks in the tread area
at temperatures below -7°C (20°
F). Always store ultra high
performance summer tires
indoors and at temperatures
above -7°C (20°F) when not in
use. If the tires have been
subjected to -7°C (20°F) or less,
let them warm up in a heated
space to at least 5°C (40°F) for
24 hours or more before being
installed or driving a vehicle on
which they are installed. Do not
apply heat or blow heated air
directly on the tires. Always
inspect tires before use. See Tire
Inspection on page 10-48.
Tire Sidewall Labeling
Useful information about a tire is
molded into its sidewall. The
examples show a typical
passenger tire sidewall.
Passenger (P-Metric) Tire Example
(1) Tire Size:The tire size is a
combination of letters and
numbers used to define a
particular tire's width, height,
aspect ratio, construction type,
and service description. See the
“Tire Size” illustration later in this
section for more detail.
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Black plate (39,1)Chevrolet SS Sedan Owner Manual (GMNA-Localizing-U.S.-7707491) - 2015 -
crc - 9/16/14
Vehicle Care 10-39
the tire size means a passenger
vehicle tire engineered to
standards set by the U.S. Tire
and Rim Association.
(2) Tire Width
:The three-digit
number indicates the tire section
width in millimeters from
sidewall to sidewall.
(3) Aspect Ratio
:A two-digit
number that indicates the tire
height-to-width measurements.
For example, if the tire size
aspect ratio is 60, as shown in
item 3 of the illustration, it would
mean that the tire's sidewall is
60 percent as high as it is wide.
(4) Construction Code
:A letter
code is used to indicate the type
of ply construction in the tire.
The letter R means radial ply
construction; the letter D means
diagonal or bias ply
construction; and the letter B
means belted-bias ply
construction. (5) Rim Diameter
:Diameter of
the wheel in inches.
(6) Service Description
:These
characters represent the load
index and speed rating of the
tire. The load index represents
the load carrying capacity a tire
is certified to carry. The speed
rating is the maximum speed a
tire is certified to carry a load.
Tire Terminology and
Definitions
Air Pressure:The amount of
air inside the tire pressing
outward on each square inch of
the tire. Air pressure is
expressed in kPa (kilopascal)
or psi (pounds per square inch).
Accessory Weight
:The
combined weight of optional
accessories. Some examples of
optional accessories are automatic transmission, power
windows, power seats, and air
conditioning.
Aspect Ratio
:The relationship
of a tire's height to its width.
Belt
:A rubber coated layer of
cords between the plies and the
tread. Cords may be made from
steel or other reinforcing
materials.
Bead
:The tire bead contains
steel wires wrapped by steel
cords that hold the tire onto
the rim.
Bias Ply Tire
:A pneumatic tire
in which the plies are laid at
alternate angles less than
90 degrees to the centerline of
the tread.
Cold Tire Pressure
:The
amount of air pressure in a tire,
measured in kPa (kilopascal)
or psi (pounds per square inch)
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Black plate (55,1)Chevrolet SS Sedan Owner Manual (GMNA-Localizing-U.S.-7707491) - 2015 -
crc - 9/16/14
Vehicle Care 10-55
Warning (Continued)
a crash. Always use the correct
wheel, wheel bolts, and wheel
nuts for replacement.
{Caution
The wrong wheel can also cause
problems with bearing life, brake
cooling, speedometer or
odometer calibration, headlamp
aim, bumper height, vehicle
ground clearance, and tire or tire
chain clearance to the body and
chassis.
Used Replacement Wheels
{Warning
Replacing a wheel with a used
one is dangerous. How it has
been used or how far it has been
driven may be unknown. It could
fail suddenly and cause a crash.
When replacing wheels, use a
new GM original equipment
wheel.
Tire Chains
{Warning
Do not use tire chains. There is
not enough clearance. Tire chains
used on a vehicle without the
proper amount of clearance can
cause damage to the brakes,
suspension, or other vehicle
parts. The area damaged by the
tire chains could cause loss of(Continued)
Warning (Continued)
control and a crash. Use another
type of traction device only if its
manufacturer recommends it for
the vehicle's tire size combination
and road conditions. Follow that
manufacturer's instructions. To
avoid vehicle damage, drive
slowly and readjust or remove the
traction device if it contacts the
vehicle. Do not spin the wheels.
If traction devices are used, install
them on the rear tires.
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