2008 SAAB 9-3 Owners Manual

249 Car care
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.
Wheel Alignment and Tire
BalanceThe wheels on your vehicle were aligned
and balanced carefully at the factory to give
you the longest tire life and best overall per-
formance.
Scheduled wheel alignment and wheel bal-
ancing are not needed. However, if you
notice unusual tire wear or your vehicle pull-
ing one way or the other, the alignment may
need to be reset. If you notice your vehicle
vibrating when driving on a smooth road,
your wheels may need to be rebalanced.
93_US_M08.book Page 249 Friday, May 11, 2007 11:37 AM
ProCarManuals.com

250 Car careWheel ReplacementReplace any wheel that is bent, cracked or
badly rusted or corroded. If wheel nuts keep
coming loose, the wheel, wheel bolts and
wheel nuts should be replaced. If the wheel
leaks air, replace it (except some aluminum
wheels, which can sometimes be repaired).
See your dealer if any of these conditions
exist.
Your dealer will know the kind of wheel you
need.
Each new wheel should have the same
load-carrying capacity, diameter, width,
offset and be mounted the same way as the
one it replaces.
If you need to replace any of your wheels,
wheel bolts or wheel nuts, replace them only
with new Saab original equipment parts.
This way, you will be sure to have the right
wheel, wheel bolts and wheel nuts for your
vehicle.Notice: The wrong wheel can also cause
problems with bearing life, brake cool-
ing, speedometer or odometer calibra-
tion, headlamp aim, bumper height, vehi-
cle ground clearance and tire or tire
chain clearance to the body and chassis.
See “Changing a tire” on page 262.Used Replacement Wheels
WARNING
Using the wrong replacement wheels,
wheel bolts or wheel nuts on your vehicle
can be dangerous. It could affect the
braking and handling of your vehicle,
make your tires lose air and make you
lose control. You could have a collision in
which you or others could be injured.
Always use the correct wheel, wheel bolts
and wheel nuts for replacement.
WARNING
When fitting just one new pair of tires,
these should be fitted to the rear wheels,
as these are more critical to the direc-
tional stability of the car (e.g. on braking
or in a skid). The existing rear wheels
should therefore be moved to the front.
WARNING
Putting a used wheel on your vehicle is
dangerous. You can’t know how it’s been
used or how far it’s been driven. It could
fail suddenly and cause a crash. If you
have to replace a wheel, use a new GM
original equipment wheel.
93_US_M08.book Page 250 Friday, May 11, 2007 11:37 AM
ProCarManuals.com

251 Car care
Tire Chains
Notice: If your vehicle does not have
235/45R17 size tires, use tire chains only
where legal and only when you must.
Contact your Saab dealer regarding suit-
able 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 instructions. If you
can hear the chains contacting 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 FlatIt’s unusual for a tire to “blowout” 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 “blowout”, 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 blowout, 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 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.93_US_M08.book Page 251 Friday, May 11, 2007 11:37 AM
ProCarManuals.com

252 Car careTire 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 the performance factors:
treadwear, traction and temperature resis-
tance. For more information see “Uniform
Tire Quality Grading” on page 248.
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 “Recommended lowest tire pres-
sure, cold tires” on page 296 and “Loading
Your Vehicle” on page 254.
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
93_US_M08.book Page 252 Friday, May 11, 2007 11:37 AM
ProCarManuals.com

253 Car care
Aspect ratio: A two-digit number that indi-
cates the tire height-to-width measure-
ments. For example, if the tire size aspect
ratio is “55”, as shown in item “C” of the illus-
tration, it would mean that the tire´s sidewall
is 55% as high as it is wide.
Belt Rating: 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 con-
struction; and the letter “B” means
belted-bias ply construction.
Rim Diameter: Diameter of the wheel in
inches.
Load range: The load range represents the
load carry capacity a tire is certified to carry.
Speed Rating: The maximum speed that a
tire is certified to carry a load. Speed ratings
range from “A” to “Z”.
Tire markingsAn example of the meaning of the different
markings in a tire size is given below for a
tire size of 225/45 R17 94H:
225 Tire section width, mm
45Aspect ratio, i.e. the section height
as a percentage of the section
width
R Radial ply
17Wheel rim diameter 17 in at bead
seats
94 Tire load index
H Speed rating
Tire load indices
91Tire approved for max. 1355 lbs.
(615 kg)
93 Max. 1433 lbs. (650 kg)
94 Max. 1477 lbs. (670 kg)
95 Max. 1521 lbs. (690 kg)
97 Max. 1609 lbs. (730 kg)Speed ratings
QTire approved for speeds up to
100 mph (160 km/h)
S Max. 112 mph (180 km/h)
T Max. 118 mph (190 km/h)
H Max. 130 mph (210 km/h)
V Max. 149 mph (240 km/h)
W Max. 168 mph (270 km/h)
Y Max. 186 mph (300 km/h)
93_US_M08.book Page 253 Friday, May 11, 2007 11:37 AM
ProCarManuals.com

254 Car care
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 centreline 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 has built up heat from driving. See
“Inflation - Tire Pressure” on page 244.
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. This label can only be found on vehicles
sold in the U.S.
Vehicles sold in Canada have the tire
information label in the glove box, see
page 297.
TIN-codea Manufacturer´s Identification Mark
b Tire Size
c Tire Type Code
d Date of Manufacture93_US_M08.book Page 254 Friday, May 11, 2007 11:37 AM
ProCarManuals.com

255 Car care
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 287.
GAWR FRT: Gross Axle Weight Rating for
the front axle, see page 287.
GAWR RR: Gross Axle Weight Rating for
the rear axle, see page 287.
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.Maximum 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 254.
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 placard, see
“Inflation - Tire Pressure” on page 244 and
“Loading Your Vehicle” on page 254.
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-
treline 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 246.93_US_M08.book Page 255 Friday, May 11, 2007 11:37 AM
ProCarManuals.com

256 Car careTread 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 248.
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 254.
Vehicle Maximum Load on the Tire: Load
on an individual tire due to curb weight,
accessory weight, occupant weight and
cargo weight.
Vehicle Placard: A label permanently
attached to a vehicle showing original
equipment tire size and the recommended
cold inflation pressure. See “Loading Your
Vehicle” on page 254.
Steps for Determining Correct
Load Limit1 Locate the statement “The
combined weight of occupants and
cargo should never exceed
XXX pounds” on your vehicle´s
placard.
2 Determine the combined weight of
the driver and passengers that will
be riding in your vehicle.
3 Substract the combined weight of
the driver and passengers from
XXX kilograms or XXX pounds.
4 The resulting figure equals the avail-
able amount of cargo and luggage
load capacity. For example, if the
“XXX” amount equals 1400 lbs. and
there will be five 150 lb. passengers
in your vehicle, the amount of avail-
able cargo and luggage load capac-
ity is 650 lbs. (1400–750 (5x150) =
650 lbs.).5 Determine the combined weight of
luggage and cargo being loaded on
the vehicle. That weight may not
safely exceed the available cargo
and luggage load capacity calcu-
lated in Step 4.
6 If your vehicle will be towing a trailer,
load from your trailer will be trans-
ferred to your vehicle. Consult this
manual to determine how this
reduces the available cargo and
luggage load capacity of your vehi-
cle.
93_US_M08.book Page 256 Friday, May 11, 2007 11:37 AM
ProCarManuals.com