
226 Car care and technical informationUniform Tire Quality GradingQuality grades can be found where applica-
ble on the tire sidewall between tread shoul-
der and maximum section width. For exam-
ple:
Treadwear 200 Traction AA
Temperature A
The following information relates to the
system developed by the United States
National Highway Traffic Safety Administra-
tion, which grades tires by treadwear, trac-
tion and temperature performance. (This
applies only to vehicles sold in the United
States.) The grades are molded on the side-
walls of most passenger car tires. The Uni-
form Tire Quality Grading system does not
apply to deep tread, winter-type snow tires,
space-saver or temporary use spare tires,
tires with nominal rim diameters of 10 to 12
inches (25 to 30 cm), or to some limited-pro-
duction tires.
While the tires available on General Motors
passenger cars and light trucks may vary
with respect to these grades, they must also
conform to federal safety requirements and
additional General Motors Tire Perfor-
mance Criteria (TPC) standards.Treadwear
The treadwear grade is a comparative
rating based on the wear rate of the tire
when tested under controlled conditions on
a specified government test course. For
example, a tire graded 150 would wear one
and a half (1.5) times as well on the govern-
ment course as a tire graded 100. The rela-
tive performance of tires depends upon the
actual conditions of their use, however, and
may depart significantly from the norm due
to variations in driving habits, service prac-
tices and differences in road characteristics
and climate.
Traction – AA, A, B, C
The traction grades, from highest to lowest,
are AA, A, B, and C. Those grades repre-
sent the tire’s ability to stop on wet pave-
ment as measured under controlled condi-
tions on specified government test surfaces
of asphalt and concrete. A tire marked C
may have poor traction performance. Warn-
ing: The traction grade assigned to this tire
is based on straight-ahead braking traction
tests, and does not include acceleration,
cornering, hydroplaning, or peak traction
characteristics.Temperature – A, B, C
The temperature grades are A (the highest),
B, and C, representing the tire’s resistance
to the generation of heat and its ability to dis-
sipate heat when tested under controlled
conditions on a specified indoor laboratory
test wheel. Sustained high temperature can
cause the material of the tire to degenerate
and reduce tire life, and excessive temper-
ature can lead to sudden tire failure. The
grade C corresponds to a level of perfor-
mance which all passenger car tires must
meet under the Federal Motor Vehicle
Safety Standard No. 109. Grades B and A
represent higher levels of performance on
the laboratory test wheel than the minimum
required by law.
Warning: The temperature grade for this tire
is established for a tire that is properly
inflated and not overloaded. Excessive
speed, underinflation, or excessive loading,
either separately or in combination, can
cause heat buildup and possible tire failure.95_US_M08.book Page 226 Friday, May 11, 2007 1:06 PM
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228 Car care and technical informationTire Chains
Notice: If your vehicle does not have
225/45R17 alt. 235/45 R17 size tires, use
tire chains only where legal and only
when you must. Contact your Saab
dealer regarding suitable snow chains.
Install them on the front tires and tighten
them as tightly as possible with the ends
securely fastened. Drive slowly and
follow the chain manufacturer’s instruc-
tions. If you can hear the chains contact-
ing your vehicle, stop and retighten
them. If the contact continues, slow
down until it stops. Driving too fast or
spinning the wheels with chains on will
damage your vehicle.If a Tire Goes Flat
It’s unusual for a tire to “blow-out” while
you’re driving, especially if you maintain
your tires properly. If air goes out of a tire,
it’s much more likely to leak out slowly. But
if you should ever have a “blow-out”, here
are a few tips about what to expect and what
to do:
If a front tire fails, the flat tire will create a
drag that pulls the vehicle toward that side.
Take your foot off the accelerator pedal and
grip the steering wheel firmly. Steer to main-
tain lane position, and then gently brake to
a stop well out of the traffic lane.
A rear blow-out, particularly on a curve, acts
much like a skid and may require the same
correction you’d use in a skid. In any rear
blowout, remove your foot from the acceler-
ator pedal. Get the vehicle under control by
steering the way you want the vehicle to go.
It may be very bumpy and noisy, but you can
still steer. Gently brake to a stop – well off
the road if possible.
If a tire goes flat, the next part shows how to
use your jacking equipment to change a flat
tire safely.
WARNING
If your vehicle has 225/45 R17 alt. 235/45
R17 size tires, don’t use tire chains,
there’s 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 you to lose
control of your vehicle and you or others
may be injured in a crash.
Use another type of traction device only if
its manufacturer recommends it for use
on your vehicle and tire size combination
and road conditions. Follow that manu-
facturer’s instructions. To help avoid
damage to your vehicle, drive slowly,
readjust or remove the device if it’s con-
tacting your vehicle, and don’t spin your
wheels.
If you do find traction devices that will fit,
install them on the front tires.95_US_M08.book Page 228 Friday, May 11, 2007 1:06 PM
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229 Car care and technical information
Tire Sidewall LabelingUseful information about a tire is molded
into it´s sidewall.
Tire size: The tire size ia a combination of
letters and numbers used to define a partic-
ular tire´s width, height, aspect ratio, con-
struction type and service description.
Department of Transportation (DOT):
The Department of Transportation (DOT)
code indicates that the tire is in compliance
with the U.S. Department of Transportation
Motor Vehicle Safety standards.
Tire Identification Number (TIN): The let-
ters and numbers following DOT code are
the Tire Identification Number (TIN). The
TIN shows the manufacturer and plant
code, tire size, and date the tire was manu-
factured. The TIN is molded onto both sides
of the tire.
Tire Ply Material: The type of cord and
number of plies in the sidewall and under
the tread.Uniform Tire Quality Grading (UTQG):
Tire manufacturers are required to grade
tires based on performance factors: tread-
wear, traction and temperature resistance.
For more information see “Uniform Tire
Quality Grading” on page 226.
Maximum Cold Inflation Load Limit: Max-
imum load that can be carried and the max-
imum pressure needed to support that load.
For information on recommended tire pres-
sure see “Lowest recommended tire pres-
sure, cold tires” on page 269and “Loading
Your Vehicle” on page 231.
Tire SizeThe following illustration shows an example
of a typical passenger car tire size.
Tire Width: The three-digit number indi-
cates the tire section width in millimeters
from sidewall to sidewall.215/55 R 16 93 H
| |||||
abcdef
aTire Width
b Aspect Ratio
c Belt Rating
d Rim diameter
e Load range
f Speed rating
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231 Car care and technical information
Loading Your VehicleThis is an example of what your vehicle´s
Tire-Loading Information/Certification label
might look like. It is located on the B-pillar
and shows how much weight your vehicle
may properly carry. The label tells you the
proper size, and recommended inflation
pressures for the tires on your vehicle. It
also gives you important information about
the number of people that can be in your
vehicle and the total weight that you can
carry. This weight is called the Vehicle
Capacity Weight, and includes the weight of
all occupants, cargo and all nonfac-
tory-installed options.
Tire Terminology and DefinitionsAir 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 com-
bined weight of optional accessories, for
example, automatic transmission, power
steering, power brakes, power windows,
power seats, radio 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 rein-
forcing materials.
Bias Ply Tire: A pneumatic tire in which the
ply cords that extend to the beads are laid at
alternate angles substantially less than 90
degrees to the centerline of the tread.
Cold Inflation Pressure: The amount of air
pressure in a tire, measured in pounds per
square inch (psi) or kilopascal (kPa), before
a tire have built up heat from driving. See
“Inflation - Tire Pressure” on page 222.
Curb weight: This means the weight of a
motor vehicle with standard and optional
equipment including the maximum capacity
of fuel, oil and coolant, without passengers
and cargo.DOT Markings: A code molded into the
sidewall of a tire signifying that the tire is in
compliance with the U.S. Department of
Transportation motor vehicle safety stan-
dards. The DOT code includes the Tire
Identification Number (TIN), an alphanu-
meric designator which can also identify the
tire manufacturer, production plant, brand
and date of production.
GVWR: Gross Vehicle Weight Rating see
page 260.
GAWR FRT: Gross Axle Weight Rating for
the front axle, see page 260.
GAWR RR: Gross Axle Weight Rating for
the rear axle, see page 260.
Intended Outboard Sidewall: The side of
an asymmetrical tire that must always face
outward when mounted on a vehicle.
Kilopascal (kPa): The metric unit for air
pressure. There are 6.9 kPa to one psi.
Light Truck (LT-Metric) Tire: A tire used
on light duty trucks and some multipurpose
passenger vehicles.
Load Index: An assigned number ranging
from 1 to 279 that corresponds to the load
carrying capacity of a tire. This label can only be found on vehicles
sold in the U.S.
Vehicles sold in Canada have the tire
information label in the glovebox, see
page 270.
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232 Car care and technical informationMaximum Load rating: The load rating for
a tire at the maximum permissible inflation
pressure for that tire.
Maximum Loaded Vehicle Weight: The
sum of curb weight; accessory weight; vehi-
cle capacity weight; and production options
weight.
Maximum Permissible Inflation Pres-
sure: The maximum cold inflation pressure
to which a tire may be inflated.
Normal occupant weight: The number of
occupants a vehicle is designed to seat mul-
tipled by 150 pounds (68 kg). See “Loading
Your Vehicle” on page 231.
Occupant Distribution: Designated seat-
ing positions.
Outward Facing Sidewall: The side of a
asymmetrical tire that has a particular side
that faces outward when mounted on a vehi-
cle. The side of the tire that contains a white-
wall bears white lettering or bears manufac-
turer, brand and or model name molding on
the other sidewall of the tire.
Passenger (P-Metric) Tire: A tire used on
passenger cars and some light duty trucks
and multipurpose vehicles.Recommended Inflation Pressure: Vehi-
cle manufacturer´s recommended tire infla-
tion pressure shown on the tire label, see
“Inflation - Tire Pressure” on page 222 and
“Loading Your Vehicle” on page 231.
Radial Ply Tire: A pneumatic tire in which
the ply cords that extend to the beads are
laid at substantially 90 degrees to the cen-
terline of the tread.
Rim: A metal support for a tire or a tire and
tube assembly upon which the tire beads
are seated.
Sidewall: The portion of a tire between the
tread and the bead.
Speed rating: An alphanumeric code
assigned to a tire indicating the maximum
speed at which a tire can operate.
Traction: The friction between the tire and
the road surface. The amount of grip pro-
vided.
Treadwear Indicators: Narrow bands,
sometimes called “wear bars”, that show
across the tread of a tire when only
2/32 inch of tread remains. See “When It Is
Time for New Tires” on page 224.Tread Width: The width of the tire´s tread.
UTQGS: Uniform Tire Quality Grade Stan-
dards, a tire information system that pro-
vides consumers with ratings for a tire´s
traction, temperature and treadwear. Rat-
ings are determined by tire manufacturers
using government testing procedures. The
rating are molded into the sidewall of the
tire. See “Uniform Tire Quality Grading” on
page 226.
Vehicle Capacity Weight: Is the number of
designated seating positions multipled by
150 pounds (68 kg) plus the rated cargo
load. See “Loading Your Vehicle” on
page 231.
Vehicle Maximum Load on the Tire: Load
on an individual tire due to curb weight,
accessory weight, occupant weight and
cargo weight.
Vehicle label: A label permanently
attached to a vehicle showing original
equipment tire size and the recommended
cold inflation pressure. See “Loading Your
Vehicle” on page 231.95_US_M08.book Page 232 Friday, May 11, 2007 1:06 PM
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234 Car care and technical informationAutomatic tire pressure
monitoring systemThe system consists of a sensor in each
wheel and a receiver. The sensors are
located inside the tire in direct connection
with the air pressure valves.
Make sure that wheels with sensors for tire
pressure monitoring are fitted during
replacement if the car has automatic tire
pressure monitoring.Tire pressure information is transmitted
wirelessly to the receiver.
The system checks the tire pressures when
speed exceeds 19 mph (30 km/h).
The system is self-programming which
means that the wheels can be shifted
around without any need for adjustment.
The spare wheel has no sensor.
The sensor batteries last for 10 years or
around 160 000 km. The battery cannot be
replaced. The whole sensor must be
replaced.
The system does not warn if the tire pres-
sure is too high.
WARNING
The system is an aid to the driver. The
driver always has the responsibility that
the tires have the correct air pressure.
For optimum safety, economy and com-
fort tire pressures should be checked reg-
ularly even if the automatic tire pressure
monitoring has not alarmed.
NOTETire replacement must take place with
great care to avoid damaging the sensors
that are built together with the valves.
Remove the rear side first.
Start to remove the tire opposite the
valve.
During removal the tire machine must
not come closer than ±10° from the
valve.
During fitting, start 20° after the valve
and finish 20° before the valve.
Do not inflate the tire with pressure
higher than 102 psi (700 kPa).
Valve with sensor
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236 Car care and technical informationMalfunctionsThe above message is shown on the SID if:
a wheel without pressure sensor has
been fitted (e.g. spare wheel)
one or more pressure sensors are broken
or missing
a fault has arisen in the receiver
a system error has arisen.
Removing a tireRemove the tire with a tire machine. It is
important to follow the instructions for the
tire machine as well.
Do not fit the tire tool in an area ±10° from
the valve.
Start removing opposite the valve.
Remove the rear side first.
Fitting a tireFit the tire with a tire machine. It is important
to follow the instructions for the tire machine
as well.
Start to fit about 20° after the valve.
Finish fitting before an area 20° from the
valve.
Do not inflate the tire to a pressure higher
than 102 psi (700 kPa). Tire pressure system
failure. Contact service.
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237 Car care and technical information
Compact spare tireThe spare tire, together with the jack, front
towrope attachment eye and toolkit, is
stowed away underneath the luggage-com-
partment floor.
The compact spare is light and easy to
handle when changing the tire. Its use is
only permitted when a standard tire has sus-
tained a puncture. The maximum life of the
tire is only 2000 miles (3,500 km).
Do not exceed 50 mph (80 km/h) with the
compact spare fitted.
The compact spare should be inflated to
60 psi (420 kPa). Carry the punctured tire in
the spare-wheel well under the luggage-
compartment floor.
Have the standard tire repaired and refitted
as soon as possible.
WARNING
Stow all tools carefully away after use, so
that they cannot get loose and cause
injury in the event of a crash.
NOTETo avoid damaging a punctured alloy
wheel it can be placed outside up in the
spare-wheel well but only while driving to
the closest dealer.
A general rule is that all heavy loads must
be well secured in the luggage compart-
ment, see page 131 and 135.
IB3233
Spare wheel (under panel in luggage
compartment)
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