tires SMART FORTWO COUPE 2008 User Guide

Tires and wheels
182
>> Operation Contact an authorized smart center for infor

mation on tested and recommended rims and
tires for summer and winter operation. They
can also offer advice concerning tire service
and purchase.
Modifications to the brake system and wheels
and the use of spacer and brake dust rings
are not permissible.
Important guidelines• Only use sets of tires and rims of the same
type and make.
• Tires must be of the correct size for the
rim.
• Break in new tires for approximately
60 miles (100 km) at moderate speeds.
• Regularly check the tires and rims for
damage. Dented or bent rims can cause tire
inflation pressure loss and damage to the
tire beads.
• If vehicle is heavily loaded, check tire infla

tion pressure and correct as required.
• Do not allow your tires to wear down too far.
Adhesion properties on wet roads are
sharply reduced at tread depths of less
than
1/8in (3 mm).
G
Warning!
Replace rims or tires with the same des

ignation, manufacturer and type as shown
on the original part. Contact an autho

rized smart center for further informa

tion. If incorrectly sized rims and tires
are mounted:
• The wheel brakes or suspension
components can be damaged.
• The operating clearance of the wheels
and the tires may no longer be correct.
G
Warning!
Worn, old tires can cause accidents. If the
tire tread is badly worn, or if the tires
have sustained damage, replace them.
When replacing rims, only use genuine
smart wheel bolts specified for the
particular rim type. Failure to do so can
result in the bolts loosening and possibly
an accident.
Retreaded tires are not tested or recom

mended by smart, since previous damage
cannot always be recognized on retreads.
The operating safety of the vehicle can

not be assured when such tires are used.

Tires and wheels
>> Operation
183 Tire care and maintenance
Regularly check your tire inflation pressure
at least once a month. For more information on
checking tire inflation pressure, see
"Recommended tire inflation pressure"
(
page 189)
.
Tire inspection
Every time you check the tire inflation pres

sure, you should also inspect your tires for
the following:
• excessive treadwear (

page 183)
• cord or fabric showing through the tire’s
rubber
• bumps, bulges, cuts, cracks or splits in the
tread or side of the tire
Replace the tire if you find any of the above
conditions.
Life of tire
The service life of a tire is dependent upon
varying factors including but not limited to:
•Driving style
• Tire inflation pressure
•Distance drivenTread depth
Do not allow your tires to wear down too far.
Adhesion properties on wet roads are sharply
reduced at tread depths of less than
1/8in
(3 mm)
.
Treadwear indicators (TWI) are required by
law. These indicators are located in six places
on the tread circumference and become visi

ble at a tread depth of approximately
1/16in
(1.6 mm), at which point the tire is considered
worn and should be replaced.
Recommended minimum tire tread depth:
Summer tires
1/8in (3 mm)
Winter tires
1/6in (4 mm)
G
Warning!
Regularly check the tires for damage.
Damaged tires can cause tire inflation
pressure loss. As a result, you could lose
control of your vehicle.
Worn, old tires can cause accidents. If the
tire tread is badly worn, or if the tires
have sustained damage, replace them.
G
Warning!
Tires should be replaced after 6 years,
regardless of the remaining tread.

Tires and wheels
184
>> Operation
1
TWI (T
read W
ear I
ndicator)
The treadwear indicator appears as a solid
band across the tread.
Storing tires
!
Keep unmounted tires in a cool, dry place
with as little exposure to light as possible.
Protect tires from contact with oil, grease and
gasoline.Cleaning tires
!
Never use a round nozzle to power wash
tires. The intense jet of water can result in
damage to the tire.
Always replace a damaged tire.
Direction of rotationUnidirectional tires offer added advantages,
such as better hydroplaning performance.
To benefit, however, you must make sure the
tires rotate in the direction specified.
An arrow on the sidewall indicates the
intended direction of rotation (spinning) of
the tire.
G
Warning!
Although the applicable federal motor
safety laws consider a tire to be worn
when the treadwear indicators (TWI) be

come visible at approximately
1/16in
(1.6 mm), we recommend that you do not
allow your tires to wear down to that
level. As tread depth approaches 1/8in
(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.

Tires and wheels
>> Operation
185 Loading the vehicle
Two labels on your vehicle show how much
weight it may properly carry.
1) The Tire and Loading Information placard
can be found on the driver’s door B
pillar.
This placard tells you important informa

tion about the number of people that can
be in the vehicle and the total weight that
can be carried in the vehicle. It also con

tains information on the proper size and
recommended tire inflation pressures for
the original equipment tires on your vehi

cle.2) The certification label, also found on the
driver’s door B
pillar, tells you about the
gross weight capacity of your vehicle,
called the Gross Vehicle Weight Rating
(GVWR). The GVWR includes the weight of
the vehicle, all occupants, fuel and cargo.
The certification label also tells you about
the front and rear axle weight capacity,
called the Gross Axle Weight Rating
(GAWR). The GAWR is the total allowable
weight that can be carried by a single axle
(front or rear). Never exceed the GVWR or
GAWR for either the front axle or rear
axle.
1
Driver’s door B
pillar
Following is a discussion on how to work with
the information contained on the Tire and
Loading Information placard with regards to
loading your vehicle.

Tires and wheels
186
>> Operation Tire and Loading InformationTire and Loading Information placard
i
Data shown on Tire and Loading Informa

tion placard example are for illustration pur

poses only. Load limit data are specific to
each vehicle and may vary from data shown in
the following illustration. Refer to Tire and
Loading Information placard on vehicle for
actual data specific to your vehicle.
1
Load limit information on the Tire and
Loading Information placardThe Tire and Loading Information placard
showing the load limit information is located
on the driver’s door B
pillar (

page 185).
>Locate the statement "The combined weight
of occupants and cargo should never
exceed XXX kg or XXX lbs." on the Tire and
Loading Information placard.
The combined weight of all occupants and
cargo / luggage should never exceed the
weight referenced in that statement.
Seating capacity
The seating capacity gives you important
information on the number of occupants that
can be in the vehicle. The Tire and Loading
Information placard showing the seating
capacity is located on the driver’s door
B
pillar (

page 185)
.
G
Warning!
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. Overload

ing the tires can overheat them, possibly
causing a blowout. Overloading the tires
can also result in handling or steering
problems, or brake failure.

Tires and wheels
>> Operation
187
i
Data shown on Tire and Loading Informa

tion placard example are for illustration pur

poses only. Seating capacity data are specific
to each vehicle and may vary from data shown
in the following illustration. Refer to Tire and
Loading Information placard on vehicle for
actual data specific to your vehicle.
1
Seating capacity information on the Tire
and Loading Information placardSteps for determining correct load limit
The following steps have been developed as
required of all manufacturers under Title 49,
Code of U.S. Federal Regulations, Part 575
pursuant to the "National Traffic and Motor
Vehicle Safety Act of 1966".
Step 1
>Locate the statement "The combined weight
of occupants and cargo should never ex

ceed XXX kg or XXX lbs." on your vehicle’s
Tire and Loading Information placard.
Step 2
>Determine the combined weight of the
driver and passenger that will be riding in
your vehicle.
Step 3
>Subtract the combined weight of the driver
and passenger from XXX kilograms or
XXX lbs.Step 4
>The resulting figure equals the available
amount of cargo and luggage load capacity.
For example, if the "XXX" amount equals
540 lbs and there will be one 150 lbs
passenger in your vehicle, the amount of
available cargo and luggage load capacity
is 390 lbs (540 lbs
150 lbs = 390 lbs).
Step 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 calculated
in step 4.
i
The maximum cargo compartment load is
100 lbs (50 kg).

Tires and wheels
188
>> Operation The following table shows examples on how to calculate total and cargo load capacities with varying seating configurations and number and size
of occupants. The following examples use a load limit of 540 lbs. This is for illustration purposes only. Make sure you are using the actual load
limit for your vehicle stated on the vehicle’s Tire and Loading Information placard (

page 186).
The higher the weight of all occupants, the less cargo and luggage load capacity is available.
Example
Combined weight
limit of occupants
and cargo from
Tire and Loading
Information
placard
Number of
occupants
(driver and
passenger)
Occupants weight
Combined weight of
all occupants
Available cargo weight (total load limit
from Tire and Loading Information
placard minus combined weight of all
occupants)
1
540 lbs
2
Occupant 1: 150 lbs
Occupant 2: 180 lbs
330 lbs
540 lbs
330 lbs = 210 lbs
2
540 lbs
1
Occupant 1: 150 lbs
150 lbs
540 lbs
150 lbs = 390 lbs

Tires and wheels
>> Operation
189
Certification label
Even after careful determination of the
combined weight of all occupants and cargo as
to not exceed the permissible load limit, you
must make sure that your vehicle never
exceeds the Gross Vehicle Weight Rating
(GVWR) and the Gross Axle Weight Rating
(GAWR) for either the front or rear axle. You
can obtain the GVWR and GAWR from the
certification label. The certification label can
be found on the driver’s door B
pillar, see
"Technical data" (

page 293).
Gross Vehicle Weight Rating (GVWR) means:
the total weight of the vehicle, all occupants,
and all cargo must never exceed the GVWR.
Gross Axle Weight Rating (GAWR) means:
the total allowable weight that can be carried
by a single axle (front or rear).To assure that your vehicle does not exceed
the maximum permissible weight limits (GVWR
and GAWR for front and rear axle), have the
loaded vehicle (including driver, passenger,
and all cargo) weighed on a suitable commer

cial scale.
Recommended tire inflation
pressure
Your vehicle is equipped with the Tire and
Loading Information placard located on the
driver’s door B
pillar (

page 185).
The tire inflation pressure should be checked
regularly and should only be adjusted on cold
tires. The tires can be considered cold if the
vehicle has been parked for at least 3 hours
or driven less than 1 mile (1.6 km).
G
Warning!
Follow recommended tire inflation
pressures.
Do not underinflate tires. Underinflated
tires wear excessively and/or unevenly,
adversely affect handling and fuel econ

omy, and are more likely to fail from being
overheated.
Do not overinflate tires. Overinflated
tires can adversely affect handling and
ride comfort, wear unevenly, increase
stopping distance, and result in sudden
deflation (blowout) because they are
more likely to become punctured or
damaged by road debris, potholes etc.
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. Overload

ing the tires can overheat them, possibly
causing a blowout. Overloading the tires
can also result in handling or steering
problems, or brake failure.

Tires and wheels
190
>> Operation Follow recommended cold tire inflation pres

sures listed on Tire and Loading Information
placard on the driver’s door B
pillar.
Keeping the tires properly inflated provides
the best handling, tread life and riding com

fort.
For more information, see "Important notes on
tire inflation pressure" (

page 190).
i
Data shown on Tire and Loading Informa

tion placard example are for illustration pur

poses only. Tire data are specific to each
vehicle and may vary from data shown in the
following illustration. Refer to Tire and Load

ing Information placard on vehicle for actual
data specific to your vehicle.
1
Tire and Loading Information placard
with recommended cold tire inflation
pressures
The Tire and Loading Information placard
lists the recommended cold tire inflation
pressures for maximum loaded vehicle weight.
The tire inflation pressures listed apply to the
tires installed as original equipment.Important notes on tire inflation pressure
Tire temperature and tire inflation pressure
are also increased while driving, depending
on the driving speed and the tire load.
Tire inflation pressure changes by approxi

mately 1.5 psi (0.1 bar) per 18°F (10°C) of air
temperature change. Keep this in mind when
checking tire inflation pressure where the
temperature is different from the outside
temperature.
G
Warning!
If the tire inflation pressure drops
repeatedly:
• Check the tires for punctures from
foreign objects.
• Check to see whether air is leaking
from the valves or from around the rim.

Tires and wheels
>> Operation
191 Checking tire inflation pressure
Regularly check your tire inflation pressure
at least once a month.
Check and adjust the tire inflation pressure
when the tires are cold. The tires can be con

sidered cold if the vehicle has been parked
for at least 3 hours or driven less than 1 mile
(1.6 km).
If you check the tire inflation pressure when
the tires are warm (the vehicle has been
driven for several miles or sitting less than
3 hours), the reading will be approximately
4 psi (0.3 bar) higher than the cold reading.
This is normal. Do not let air out to match the
specified cold tire inflation pressure. Other

wise, the tire will be underinflated.Checking tire inflation pressure manually
Follow the steps below to achieve correct tire
inflation pressure:
>Remove the cap from the valve on one tire.
>Firmly press a tire gauge onto the valve.
>Read tire inflation pressure on tire gauge
and check against the recommended tire
inflation pressure on the Tire and Loading
Information placard on the driver’s door
B
pillar (

page 185). If necessary, add air
to achieve the recommended tire inflation
pressure.
i
If you have overfilled the tire, release tire
inflation pressure by pushing the metal stem
of the valve with e.g. a tip of a pen. Then
recheck the tire inflation pressure with the
tire gauge.
>Install the valve cap.
>Repeat this procedure for each tire.
G
Warning!
Follow recommended tire inflation
pressures.
Do not underinflate tires. Underinflated
tires wear excessively and/or unevenly,
adversely affect handling and fuel econ

omy, and are more likely to fail from being
overheated.
Do not overinflate tires. Overinflated
tires can adversely affect handling and
ride comfort, wear unevenly, increase
stopping distance, and result in sudden
deflation (blowout) because they are
more likely to become punctured or
damaged by road debris, potholes etc.
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. Overload

ing the tires can overheat them, possibly
causing a blowout. Overloading the tires
can also result in handling or steering
problems, or brake failure.