Tire width
Tire width 0046 indicates the nominal tire
width in mm.
Aspect ratio
Aspect ratio 0047 is the dimensional
relationship between tire section height
and section width and is expressed as a
percentage. The aspect ratio is arrived at
by dividing section height by section
width.
Tire code
Tire code 008A indicates the tire
construction type. The “R” stands for radial
tire type. Letter “D” means diagonal or
bias ply construction; letter “B” means
belted-bias ply construction.
At the tire manufacturer’s option, any tire
with a speed capability above 149 mph
(240 km/h) can include a “ZR” in the size
designation (for example: 245/40 ZR 18).
For additional information, see “Tire
speed rating” ( Y page 127).
Rim diameter
Rim diameter 0088 is the diameter of the
bead seat, not the diameter of the rim edge.
Rim diameter is indicated in inches (in).
Tire load ratingGWarning!
The tire load rating must always be at least
half of the GAWR of your vehicle. Otherwise,
tire failure may result and cause an
accident and/or serious personal injury to
you or others.
Always replace rims and tires with the same
designation, manufacturer and type as
shown on the original part.
GWarning!
Do not overload the tires by exceeding the
specified load limit as indicated on the
Tire and Loading Information placard on
the driver’s door B‑pillar. Overloading the
tires can overheat them, possibly causing
a blowout. Overloading the tires can also
result in handling or steering problems, or
brake failure.
Tire load rating 0086 is a numerical code
associated with the maximum load a tire
can support.
For example, a load rating of 91
corresponds to a maximum load of 1 356 lbs
(615 kg) the tire is designed to support.
See also “Maximum tire load” ( Y page 122)
where the maximum load associated with
the load index is indicated in kilograms
and lbs.
For additional information on tire load
rating, see “Load identification”
( Y page 128).
Tire speed rating GWarning!
Even when permitted by law, never operate
a vehicle at speeds greater than the
maximum speed rating of the tires.
Exceeding the maximum speed for which
tires are rated can lead to sudden tire
failure, causing loss of vehicle control and
possibly resulting in an accident and/or
personal injury and possible death, for you
and for others.
Regardless of the tire speed rating, local
speed limits should be obeyed. Use prudent
driving speeds appropriate to prevailing
conditions.
Tire speed rating 0087 indicates the
approved maximum speed for the tire.
Summer tires
IndexSpeed ratingQup to 100 mph (160 km/h)Rup to 106 mph (170 km/h)Sup to 112 mph (180 km/h)Tup to 118 mph (190 km/h)Tires and wheels127>> Operation.451_AKB; 3; 22, en-USd2ureepe,Version: 2.11.8.12009-07-27T09:36:34+02:00 - Seite 127Z
IndexSpeed ratingHup to 130 mph (210 km/h)Vup to 149 mph (240 km/h)Wup to 168 mph (270 km/h)Yup to 186 mph (300 km/h)ZR...Yabove 186 mph (300 km/h)ZR...(Y)above 186 mph (300 km/h)ZRabove 149 mph (240 km/h)
RAt the tire manufacturer’s option, any
tire with a speed capability above
149 mph (240 km/h) can include a “ZR” in
the size designation (for example:
245/40 ZR18). To determine the maximum
speed capability of the tire, the service
description for the tire must be referred
to.
The service description is comprised of
tire load rating 0086 and tire speed rating
0087 .
If your tire includes “ZR” in the size
designation and no service description
is given, the tire manufacturer must be
consulted for the maximum speed
capability.
If a service description is given, the
speed capability is limited by the speed
symbol in the service description.
Example: 245/40 ZR18 97Y.
In this example, “97Y” is the service
description. The letter “Y” designates
the speed rating and the speed
capability of the tire is limited to
186 mph (300 km/h).
R Any tire with a speed capability above
186 mph (300 km/h) must include a “ZR” in
the size designation AND the service
description must be placed in
parenthesis. Example:
275/40 ZR 18 (99Y). The “(Y)” speed rating
in parenthesis designates the maximum
speed capability of the tire as being
above 186 mph (300 km/h). Consult the tire
manufacturer for the actual maximum
permissible speed of the tire.
All-season and winter tiresIndexSpeed ratingQ M+S 15up to 100 mph (160 km/h)T M+S15up to 118 mph (190 km/h)H M+S 15up to 130 mph (210 km/h)V M+S15up to 149 mph (240 km/h)
i
Not all M+S rated tires provide special
winter performance. Make sure the tires
you use show M+S and the mountain/
snowflake marking 004D on the tire
sidewall. These tires meet specific snow
traction performance requirements of
the Rubber Manufacturers Association
(RMA) and the Rubber Association of
Canada (RAC) and have been designed
specifically for use in snow conditions.
Load identification
i For illustration purposes only. Actual
data on tires are specific to each vehicle
and may vary from data shown in above
illustration.
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In addition to the tire load rating, special
load identification 0046 may be molded into
the tire sidewall following the letter
designating the tire speed rating 0087
( Y page 127).
No specification given: absence of any text
(like in above example) indicates a
standard load (SL) tire.
XL or Extra Load: designates an extra load
(or reinforced) tire.
Light Load: designates a light load tire.
C, D, E: designates load range associated
with the maximum load a tire can carry at a
specified pressure.
DOT, Tire Identification Number (TIN)
U.S. tire regulations require each new tire
manufacturer or tire retreader to mold a
TIN into or onto a sidewall of each tire
produced.
The TIN is a unique identifier which
facilitates efforts by tire manufactures to
notify purchasers in recall situations or
other safety matters concerning tires and
gives purchasers the means to easily
identify such tires.
The TIN is comprised of “Manufacturer’s
identification mark” 0047, “Tire size” 008A,
“Tire type code” 0088, and “Date of
manufacture” 0086.
i For illustration purposes only. Actual
data on tires are specific to each vehicle
and may vary from data shown in above
illustration.
DOT (Department of Transportation)
Tire branding symbol 0046 which denotes the
tire meets requirements of the U.S.
Department of Transportation.
Manufacturer’s identification mark
Manufacturer’s identification mark 0047
denotes the tire manufacturer.
New tires have a mark with two symbols.
Retreaded tires have a mark with four
symbols. For more information on
retreaded tires ( Y page 114).
Tire size
Code 008A indicates the tire size.
Tire type code
Tire type code 0088 may, at the option of the
manufacturer, be used as a descriptive
code for identifying significant
characteristics of the tire.
Date of manufacture
Date of manufacture 0086 identifies the week
and year of manufacture.
The first two figures identify the week,
starting with “01” to represent the first
full week of the calendar year. The second
two figures represent the year.
For example, “3202” represents the 32nd
week of 2002.
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Tire ply material
iFor illustration purposes only. Actual
data on tires are specific to each vehicle
and may vary from data shown in above
illustration.
This marking tells you about the type of
cord and number of plies in the
sidewall 0046 and under the tread 0047.
Tire and loading terminology
Accessory weight
The combined weight (in excess of those
standard items which may be replaced) of
automatic transmission, power steering,
power brakes, power windows, power seats,
radio, and heater, to the extent that these
items are available as factory-installed
equipment (whether installed or not).
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) or bars.
Aspect ratio
Dimensional relationship between tire
section height and section width expressed
in percentage.
Bar
Another metric unit for air pressure. There
are 14.5038 pounds per square inch (psi) to
1 bar; there are 100 kilopascals (kPa) to
1 bar.
Bead
The tire bead contains steel wires wrapped
by steel cords that hold the tire onto the
rim.
Cold tire inflation pressure
Tire inflation pressure when your vehicle
has been sitting for at least 3 hours or
driven no more than 1 mile (1.6 km).
Curb weight
The weight of a motor vehicle with standard
equipment including the maximum
capacity of fuel, oil, and coolant, and, if
so equipped, air conditioning and
additional optional equipment, but
without passengers and cargo.
DOT (Department of Transportation)
A tire branding symbol which denotes the
tire meets requirements of the U.S.
Department of Transportation.
GAWR (Gross Axle Weight Rating)
The GAWR is the maximum permissible axle
weight. The gross vehicle weight on each
axle must never exceed the GAWR for the
front and rear axle indicated on the
certification label located on the driver’s
door B‑pillar.
GVW (Gross Vehicle Weight)
The GVW comprises the weight of the
vehicle including fuel, tools, installed
accessories, passengers and cargo. The
GVW must never exceed the GVWR indicated
on the certification label located on the
driver’s door B‑pillar.
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GVWR (Gross Vehicle Weight Rating)
This is the maximum permissible vehicle
weight of the fully loaded vehicle (weight
of the vehicle including all options,
passengers, fuel, and cargo. It is indicated
on certification label located on the
driver’s door B‑pillar.
Kilopascal (kPa)
The metric unit for air pressure. There are
6.9 kPa to 1 psi; another metric unit for air
pressure is bars. There are
100 kilopascals (kPa) to 1 bar.
Maximum load rating
The maximum load in kilograms and pounds
that can be carried by the tire.
Maximum loaded vehicle weight
The sum of curb weight, accessory weight,
total load limit and production options
weight.
Maximum permissible tire inflation
pressure
This number is the greatest amount of air
pressure that should ever be put in the tire.
Normal occupant weight
The number of occupants the vehicle is
designed to seat, multiplied by
68 kilograms (150 lbs).
Occupant distribution
The distribution of occupants in a vehicle
at their designated seating positions.
Production options weight
The combined weight of those installed
regular production options weighing over
5 lbs (2.3 kilograms) in excess of those
standard items which they replace, not
previously considered in curb weight or
accessory weight, including heavy duty
brakes, ride levelers, roof rack, heavy duty
battery, and special trim.
PSI (Pounds per square inch)
A standard unit of measure for air
pressure.
Recommended tire inflation pressure
The recommended tire inflation pressure
for normal driving conditions is listed on
the Tire and Loading Information placard
located on driver’s door B‑pillar and
provides best handling, tread life and
riding comfort.
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.
TIN (Tire Identification Number)
Unique identifier which facilitates
efforts by tire manufacturers to notify
purchasers in recall situations or other
safety matters concerning tires and gives
purchasers the means to easily identify
such tires. The TIN is comprised of
“Manufacturer’s identification mark”,
“Tire size”, “Tire type code” and “Date of
manufacture”.
Tire load rating
Numerical code associated with the
maximum load a tire can support.
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effectiveness of the ABS and ESP®
in winter
operation.
For safe handling, make sure all mounted
winter tires are of the same make and have
the same tread design.
For information on winter tires for your
vehicle model, see the "Technical data"
section ( Y page 202).
Always observe the speed rating of the
winter tires installed on your vehicle. If
the maximum speed for which your tires are
rated is below the speed rating of your
vehicle, you must place a notice to this
effect where it will be seen by the driver.
Such notices are available at your tire
dealer or any authorized smart center.
Snow chains*
! Remember that snow chains must always
be compatible with the tire sizes of a
vehicle. Snow chains that are approved
by smart are only permitted for the
following tire size:
175/55 R15 on the rear axle.
For safety reasons, smart recommends
that you only use snow chains that have
been approved by smart.
Information on this is available from any
smart center.
Please refer to the separate operating
instructions for detailed information on
mounting the snow chains.
Snow chains should only be driven on
snow-covered roads at speeds not to
exceed 30 mph (50 km/h). Remove chains
as soon as possible when driving on roads
without snow.
Please observe the following guidelines
when using snow chains:
R Using snow chains is not permissible
with all wheel/tire combinations
( Y page 202).
R Use snow chains in pairs and on rear
wheels only. Follow the manufacturer’s
mounting instructions.
! If snow chains are mounted to the front
wheels, they may scrape against the body
or axle components. The tires or the
vehicle could be damaged as a result.
R Use of snow chains may be prohibited
depending on location. Always check
local and state laws before mounting
snow chains.GWarning!
When mounting or removing snow chains,
always park your vehicle on level ground,
engage the parking brake, and turn off the
engine. The vehicle could otherwise move
and injure yourself or other road users.
GWarning!
When mounting and removing snow chains,
ensure that you and your vehicle are at a
safe distance from moving traffic. Not
doing so could endanger other road users or
even lead to you being injured by the
vehicles behind you.
GWarning!
The vehicle’s handling changes when
driving with snow chains on any kind of
road surface. This means that you should
always adapt your driving style to suit the
current road and weather conditions.
! If snow chains that do not meet
requirements are mounted, they may
scrape against the body or axle
components when the vehicle is in
motion. This could result in damage to
the rim/tire or vehicle.
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Driving instructions
Drinking and driving
GWarning!
Do not drink alcohol or take drugs and drive
or allow anyone to drive who has been
drinking alcohol or taking drugs. Even a
small amount of alcohol or drugs can affect
your reflexes, perceptions and judgment.
The possibility of a serious or even fatal
accident are greatly increased when you
drink or take drugs and drive.
Pedals
GWarning!
Make sure absolutely no objects are
obstructing the pedals’ range of motion.
Keep the driver’s footwell clear of all
obstacles. If there are any floormats* or
carpets in the footwell, make sure the
pedals still have sufficient clearance.
During sudden acceleration or braking
maneuvers, the objects could get caught
between or beneath the pedals and restrict
your ability to brake or accelerate. This
could lead to accidents and/or injury.
Power assistance
GWarning!
With the engine not running, there is no
power assistance for the brake and
steering* systems. In this case, it is
important to keep in mind that a
considerably higher degree of effort is
necessary to brake and steer the vehicle.
Adapt your driving accordingly.
BrakesGWarning!
Make sure not to endanger any other road
users when carrying out braking
maneuvers.
Refer to the description of the hydraulic
brake assistant ( Y page 46).
! Because the ESP ®
operates
automatically, the engine must be turned
off (ignition switched off) when the
parking brake is being tested on a brake
test dynamometer. Active braking action
through the ESP ®
may otherwise seriously
damage the brake system which is not
covered by the smart Limited Warranty.
Brake pad wear or a leak in the brake system
may be the reason for low brake fluid level
in the brake fluid reservoir.
The brake fluid level in the brake fluid
reservoir may be too low if the brake
warning lamp in the instrument cluster
comes on ( Y page 22) although the parking
brake is released.
Have the brake system inspected
immediately. Contact an authorized smart
center.
All checks and service work on the brake
system should be carried out by qualified
technicians only. Contact an authorized
smart center.
Only install brake pads and use brake fluid
recommended by smart.
Inclines
! When driving down long and steep
grades, relieve the load on the brakes by
shifting into a lower gear to use the
engine’s braking power. This helps
prevent overheating of the brakes and
reduces brake pad wear.
When using the engine’s braking power, a
drive wheel may not spin for an extended
period of time, e.g. on slippery road
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RNever run the fuel tank empty.
R If the engine starts to misfire, bring the
vehicle to an immediate standstill
without endangering traffic.
R If the engine fails to start the first time,
you should not try to start it any more
than three times in succession.
R Do not try to start for more than four
seconds at a time.
Tires
GWarning!
If you feel a sudden significant vibration
or ride disturbance, or you suspect that
possible damage to your vehicle has
occurred, you should turn on the hazard
warning flashers, carefully slow down, and
drive with caution to an area which is a safe
distance from the road.
Inspect the tires and the vehicle underbody
for possible damage. If the vehicle or tires
appear unsafe, have the vehicle towed to the
nearest smart center or tire dealer for
repairs.
Treadwear indicators (TWI) are required by
law. These indicators are located in six
places on the tread circumference and
become visible at a tread depth of
approximately 1
/ 16 in (1.6 mm), at which
point the tire is considered worn and
should be replaced.
The treadwear indicator appears as a solid
band across the tread.
GWarning!
Although the applicable federal motor
vehicle safety laws consider a tire to be
worn when the treadwear indicators (TWI)
become visible at approximately 1
/ 16 in
(1.6 mm), we recommend that you do not allow
your tires to wear down to that level. As
tread depth approaches 1
/ 8 in (3 mm), the
adhesion properties on a wet road are
sharply reduced.
Depending upon the weather and/or road
surface (conditions), the tire traction
varies widely.
Specified tire inflation pressures must be
maintained. This applies particularly if
the tires are subject to high loads (e.g.
high speeds, heavy loads, high ambient
temperatures).GWarning!
Do not drive with a flat tire. A flat tire will
affect your ability to steer or brake and may
cause you to lose control of the vehicle.
Continued driving with a flat tire or
driving at high speed with a flat tire will
cause excessive heat build-up and possibly
a fire.
For more information, see “Tires and
wheels” ( Y page 114).
Hydroplaning
Depending on the depth of the water layer
on the road, hydroplaning may occur
resulting in a loss of control, even at low
speeds and with new tires. Reduce vehicle
speed, avoid track grooves in the road and
apply brakes cautiously when it is raining.
Tire traction
The safe speed on a wet, snow covered or icy
road is always lower than on a dry road.
You should pay particular attention to the
condition of the road whenever the outside
temperatures are close to the freezing
point.
GWarning!
If ice has formed on the road, tire traction
will be substantially reduced. Under such
weather conditions, drive, steer and brake
with extreme caution.
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