air condition SATURN ASTRA 2009 Owner's Manual
[x] Cancel search | Manufacturer: SATURN, Model Year: 2009, Model line: ASTRA, Model: SATURN ASTRA 2009Pages: 314, PDF Size: 1.94 MB
Page 228 of 314

Tire Size
The following illustration shows
an example of a typical
passenger vehicle tire size.
(A) Passenger (P-Metric) Tire
:The United States version of
a metric tire sizing system.
The letter P as the rst
character in the tire size
means a passenger vehicle tire
engineered to standards set
by the U.S. Tire and Rim
Association.
(B) Tire Width
:The three-digit
number indicates the tire
section width in millimeters from
sidewall to sidewall.
(C) 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 C of the illustration, it would
mean that the tire’s sidewall is
60 percent as high as it is wide.
(D) 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.
(E) Rim Diameter
:Diameter of
the wheel in inches.
(F) Service Description
:These characters represent the
load index and speed rating
of the tire. The load index
represents the load carry
capacity a tire is certi ed to
carry. The speed rating is the
maximum speed a tire is certi ed
to carry a load.
Tire Terminology and
De nitions
Air Pressure:The amount of
air inside the tire pressing
outward on each square inch
of the tire. Air pressure is
expressed in pounds per square
inch (psi) or kilopascal (kPa).
Accessory Weight
:This means
the combined weight of optional
accessories. Some examples
of optional accessories are,
automatic transmission, power
steering, power brakes, 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 that is located between the
plies and the tread. Cords may
be made from steel or other
reinforcing materials.
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When to Check
Check your tires once a month
or more. Do not forget to
check the compact spare tire,
it should be at 60 psi (420 kPa).
For additional information
regarding the compact spare
tire, seeCompact Spare Tire
on page 9-68.
How to Check
Use a good quality pocket-type
gage to check tire pressure.
You cannot tell if your tires are
properly in ated simply by
looking at them. Radial tires
may look properly in ated even
when they are under-in ated.
Check the tire’s in ation
pressure when the tires are
cold. Cold means your vehicle
has been sitting for at least
three hours or driven no more
than 1 mile (1.6 km).Remove the valve cap from
the tire valve stem. Press the tire
gage rmly onto the valve to
get a pressure measurement.
If the cold tire in ation pressure
matches the recommended
pressure on the Tire and
Loading Information label, no
further adjustment is necessary.
If the in ation pressure is low,
add air until you reach the
recommended amount.
If you over ll the tire, release air
by pushing on the metal stem
in the center of the tire valve.
Re-check the tire pressure with
the tire gage.
Be sure to put the valve caps
back on the valve stems.
They help prevent leaks by
keeping out dirt and moisture.High-Speed Operation
{CAUTION
Driving at high speeds, 100 mph
(160 km/h) or higher, puts an
additional strain on tires.
Sustained high-speed driving
causes excessive heat build up
and can cause sudden tire failure.
You could have a crash and
you or others could be killed.
Some high-speed rated tires
require in ation pressure
adjustment for high speed
operation. When speed limits and
road conditions are such that a
vehicle can be driven at high
speeds, make sure the tires are
rated for high speed operation, in
excellent condition, and set to the
correct cold tire in ation pressure
for the vehicle load.
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Tire Pressure Monitor
Operation
This vehicle may have a Tire
Pressure Monitor System (TPMS).
The TPMS is designed to warn
the driver when a low tire pressure
condition exists. TPMS sensors
are mounted onto each tire and
wheel assembly, excluding the
spare tire. The TPMS sensors
monitor the air pressure in the
vehicle’s tires and transmit tire
pressure readings to a receiver
located in the vehicle.
When a low tire pressure condition
is detected, the TPMS illuminates
the low tire pressure warning
light located in the instrument
panel cluster.The low tire pressure warning light
comes on at each ignition cycle
until the tires are in ated to
the correct in ation pressure.
The low tire pressure warning light
may come on in cool weather
when the vehicle is rst started, and
then turn off as you start to drive.
This could be an early indicator that
the air pressure in the tire(s) are
getting low and need to be in ated
to the proper pressure.
You must begin driving before the
TPMS system is operational.
TPMS sensors need to be installed
onto the full-size tire and wheel
assemblies, and the tires adjusted
to the manufacturers’ recommended
tire pressure amount.
A Tire and Load Information label is
attached to the vehicle, and
shows the size of the vehicle’s
original equipment tires and
the correct in ation pressure for the
tires when they are cold. See
Loading the Vehicle on page 8-30,
for an example of the Tire andLoad Information label and its
location on the vehicle. Also see
Inflation - Tire Pressure on
page 9-47.
The vehicle’s TPMS can warn you
about a low tire pressure condition
but it does not replace normal
tire maintenance. SeeTire
Inspection and Rotation on
page 9-52andTires on page 9-40.
Notice:Liquid tire sealants
could damage the Tire Pressure
Monitor System (TPMS) sensors.
Sensor damage caused by
using a tire sealant is not covered
by your warranty. Do not use
liquid tire sealants.
Each TPMS sensor has a unique
identi cation code. Any time
you replace one or more of the
TPMS sensors or rotate the
vehicle’s tires, the identi cation
codes are automatically learned by
the TPMS. This occurs within a
few moments of driving the vehicle
over 19 mph (31 km/h).
Vehicle Service and Care 9-51
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