2008 SMART FORTWO COUPE tire pressure

Driving safety systems
72
>> Safety.
i
In winter operation, the maximum effec

tiveness of the ABS, the hydraulic brake
assistant and the ESP
® is only achieved with
winter tires (

page 208) or snow chains* as
required.
Antilock brake system (ABS)The A
ntilock B
rake S
ystem (ABS) regulates the
brake pressure so that the wheels do not lock
during braking. This allows you to maintain the
ability to steer your vehicle.
On slippery road surfaces, the ABS will
respond even to light brake pressure.
The ABS indicator lamp in the instrument
cluster (

page 34) comes on when you switch
on the ignition. It goes out when the engine is
running.Braking
At the instant one of the wheels is about to
lock up, a slight pulsation can be felt in the
brake pedal, indicating that the ABS is regu

lating the brake pressure.
>Keep firm and steady pressure on the brake
pedal while experiencing the pulsation.
Continuous, steady brake pedal pressure
yields the advantages provided by the ABS,
namely braking power and the ability to steer
the vehicle.
A pulsating brake pedal can be an indication
of hazardous road conditions and functions as
a reminder to take extra care while driving.
G
Warning!
The following factors increase the risk of
accidents:
• Excessive speed, especially in turns
• Wet and slippery road surfaces
• Following another vehicle too closely
The driving safety systems described in
this section cannot reduce these risks or
prevent the natural laws of physics from
acting on the vehicle.
Always adapt your driving style to the
prevailing road and weather and traffic
conditions and keep a safe distance to
other road users and objects on the
street.
G
Warning!
Do not pump the brake pedal. Use firm,
steady brake pedal pressure instead.
Pumping the brake pedal defeats the
purpose of the ABS and significantly
reduces braking effectiveness.

Driving safety systems
>> Safety.
73
Emergency brake maneuver
>Keep continuous full pressure on the brake
pedal.
Electronic Stability Program
(ESP)Your vehicle is equipped with the E
lectronic
S
tability P
rogram (ESP
®). The ESP
® is opera

tional as soon as the engine is running and it
monitors the vehicle’s traction (force of ad

hesive friction between the tires and the road
surface) and handling.
The ESP
® recognizes when a wheel is spinning
or if the vehicle starts to skid.
By applying brakes to the appropriate wheel
and by limiting the engine output, the ESP
®
works to stabilize the vehicle.
The ESP
® is especially useful while driving off
and on wet or slippery road surfaces.
The ESP® also stabilizes the vehicle during
braking and steering maneuvers.
The ESP® warning lampv in the instrument
cluster flashes when the ESP
® is engaged.
G
Warning!
When the ABS is malfunctioning, the
hydraulic brake assistant and the ESP
®
are also switched off.
When the ABS is malfunctioning, the
wheels may lock during hard braking,
reducing steering capability and extend

ing the braking distance.
G
Warning!
The ABS cannot prevent the natural laws
of physics from acting on the vehicle, nor
can it increase braking or steering effi

ciency beyond that afforded by the con

dition of the vehicle brakes and tires or
the traction afforded. The ABS cannot
prevent accidents, including those
resulting from excessive speed in turns,
following another vehicle too closely, or
hydroplaning. Only a safe, attentive, and
skillful driver can prevent accidents. The
capabilities of an ABS equipped vehicle
must never be exploited in a reckless or
dangerous manner which could jeopar

dize the user’s safety or the safety of
others.

Driving safety systems
>> Safety.
75
!
Because the ESP
® operates automatically,
the engine must be turned off (key in starter
switch position0) when
• the parking brake is being tested on a
brake test dynamometer,
• the vehicle is being towed with the front
axle raised.
Active braking action through the ESP
® may
otherwise seriously damage the brake system
on the rear axle.
i
The ESP
® wi ll on l y f un cti on p ro p er ly if you
use wheels of the recommended tire size
(

page 299).
Hydraulic brake assistantThe hydraulic brake assistant operates in
emergency situations. If you apply the brakes
very quickly, the hydraulic brake assistant
automatically provides full brake boost,
thereby potentially reducing the braking
distance.
>Apply continuous full braking pressure
until the emergency braking situation is
over.
The ABS will prevent the wheels from
locking.When you release the brake pedal, the brakes
function again as normal. The hydraulic brake
assistant is then deactivated.
G
Warning!
When the hydraulic brake assistant is
malfunctioning, the brake system is still
functioning normally, but without the
additional brake boost that would nor

mally be provided during an emergency
braking maneuver. Therefore, the brak

ing distance may increase.

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
>> 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
>> 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.