2008 SMART FORTWO COUPE wheel size

Tires and wheels
>> Operation
197
General:
Depending on the design standards used, the
tire size molded into the sidewall may have no
letter or a letter preceding the tire size des

ignation.
No letter preceding the size designation
(as illustrated above): Passenger car tire
based on European design standards.
Letter "P" preceding the size designation:
Passenger car tire based on U.S. design
standards.
Letter "LT" preceding the size designation:
Light Truck tire based on U.S. design
standards.
Letter "T" preceding the size designation:
Temporary spare tires which are high
pressure compact spares designed for
temporary emergency use only.
Tire width
Tire width1
(
page 196) indicates the
nominal tire width in mm.Aspect ratio
Aspect ratio2
(
page 196) is the dimen

sional relationship between tire section
height and section width and is expressed in
percentage. The aspect ratio is arrived at by
dividing section height by section width.
Tire code
Tire code3 (

page 196) 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" (

page 198)
.
Rim diameter
Rim diameter4 (

page 196) is the diameter
of the bead seat, not the diameter of the rim
edge. Rim diameter is indicated in inches (in).Tire load rating
Tire load rating5 (

page 196) is a numeri

cal 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" (

page 201)
where the maximum load associated with the
load index is indicated in kilograms and lbs.
G
Warning!
The tire load rating must always be at
least half of the GAWR (

page 205) of
your vehicle. Otherwise, tire failure may
result and cause an accident and/or seri

ous personal injury to you or others.
Always replace rims and tires with the
same designation, manufacturer and type
as shown on the original part.

Tires and wheels
>> Operation
199
• 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 ZR18). To
determine the maximum speed capability of
the tire, the service description for the tire
must be referred to. The service descrip

tion is comprised of tire load rating5
(

page 196) and tire speed rating6
(
page 196).
If your tire includes "ZR" in the size
designation and no service description5
and6 (

page 196) is given, the tire
manufacturer must be consulted for the
maximum speed capability.
If a service description5 and6
(

page 196) 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).• 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 be

ing above 186 mph (300 km/h). Consult the
tire manufacturer for the actual maximum
permissible speed of the tire.All
season and winter tires
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.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.Index
Speed rating
Q M+S
1
1 or M+S.for winter tires
up to 100 mph (160 km/h)
T M+S
1
up to 118 mph (190 km/h)
H M+S
1
up to 130 mph (210 km/h)
V M+S
1
up to 149 mph (240 km/h)

Tires and wheels
200
>> Operation Load identification
1
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.
In addition to the tire load rating, special load
identification1 may be molded into the tire
sidewall following the letter designating the
tire speed rating (

page 196).No specification given: absence of any text
(like in above example) indicates a standard
load (SL) tire.
XL (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 speci

fied 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", "Tire size", "Tire type
code", and "Date of manufacture".
1
DOT
2
Manufacturer’s identification mark
3
Tire size
4
Tire type code (at the option of the tire
manufacturer)
5
Date of manufacture
i
For illustration purposes only. Actual data
on tires are specific to each vehicle and may
vary from data shown in above illustration.

Tires and wheels
>> Operation
201
DOT (D
epartment o
f T
ransportation)
Tire branding symbol1 (

page 200) which
denotes the tire meets requirements of the
U.S. Department of Transportation.
Manufacturer’s identification mark
Manufacturer’s identification mark2
(

page 200) 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 (

page 182).
Tire size
Code3 (
page 200) indicates the tire size.
Tire type code
Code4 (
page 200) may, at the option of
the manufacturer, be used as a descriptive
code for identifying significant characteris

tics of the tire.
Date of manufacture
Date of manufacture5 (

page 200)
identifies the week and year of manufacture.The first two figures identify the week, start

ing 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.
Maximum tire load
1
Maximum tire load rating
i
For illustration purposes only. Actual data
on tires are specific to each vehicle and may
vary from data shown in above illustration.The maximum tire load is the maximum weight
the tires are designed to support.
For more information on tire load rating
(

page 197).
For information on calculating total and cargo
load capacities (

page 187).
G
Warning!
Do not overload the tires by exceeding
the specified load limit as indicated on
the Tire and Loading Information placard
located 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.

Tires and wheels
206
>> Operation PSI (Pounds per s
quare i
nch)
A standard unit of measure for air pressure

> bar, kilopascal (kPa).
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 (T
ire I
dentification N
umber)
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.
Tire ply composition and material used
This indicates the number of plies or the num

ber of layers of rubber
coated fabric in the
tire tread and sidewall. Tire manufacturers
also must indicate the ply materials in the tire
and sidewall, which include steel, nylon, poly

ester, and others.Tire speed rating
Part of tire designation; indicates the speed
range for which a tire is approved.
Total load limit
Rated cargo and luggage load plus
68 kilograms (150 lbs) times the vehicle’s
designated seating capacity.
Traction
Force exerted by the vehicle on the road via
the tires. The amount of grip provided.
Tread
The portion of a tire that comes into contact
with the road.
Treadwear indicators
Narrow bands, sometimes called "wear bars"
that show across the tread of a tire when only
1/16in (1.6 mm) of tread remains.

Tires and wheels
>> Operation
207
Uniform Tire Quality Grading Standards
A tire information system that provides
consumers with ratings for a tire’s traction,
temperature and treadwear. Ratings are
determined by tire manufacturers using
government testing procedures. The ratings
are molded into the sidewall of the tire.
Vehicle maximum load on the tire
Load on an individual tire that is determined
by distributing to each axle its share of the
maximum loaded vehicle weight and dividing it
by two.
Rotating tiresThoroughly clean the mounting face of the
wheels and brake disks, i.e. the inner side of
the wheels/tires each time the wheels/tires
are changed. Check for and ensure proper
tire inflation pressure.For information on wheel change, see "Flat
tire" (

page 265).
G
Warning!
Do not rotate front and rear wheels as
they have different dimensions, e.g. rim
size, wheel offset etc. Otherwise, the
handling can be affected and you could
endanger yourself and others.
G
Warning!
Have the tightening torque checked after
changing a wheel. Wheels could become
loose if not tightened with a torque of
81 lb
ft (110 Nm).
Only use genuine smart wheel bolts
specified for your vehicle’s rims.

Winter driving
>> Operation
209 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:
• Using snow chains is not permissible with all
wheel/tire combinations (

page 299).
• 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.
• Use of snow chains may be prohibited
depending on location. Always check local
and state laws before mounting snow
chains.
G
Warning!
When mounting or removing snow chains,
always park your vehicle on level ground,
set the parking brake and turn off the en

gine. The vehicle could otherwise move
and injure yourself or other road users.G
Warning!
When mounting and removing snow
chains, ensure that you and your vehicle
are at a safe distance from moving traf

fic. Not doing so could endanger other
road users or even lead to you being
injured by the vehicles behind you.

Driving instructions
218
>> Operation
Tire speed ratingRegardless of the tire speed rating, local
speed limits should be obeyed. Use prudent
driving speeds appropriate to prevailing
conditions.
An electronic speed limiter prevents your
vehicle from exceeding a speed of 90 mph
(145 km/h).The factory equipped tires on your vehicle
may have a tire speed rating above the maxi

mum speed permitted by the electronic speed
limiter.
Make sure your tires have the required tire
speed rating as specified for your vehicle in
t h e " T e c h n i c a l d a t a s e c t i o n " (

page 299), for
example when purchasing new tires.
For information on how to identify the tire
speed rating on a tire’s sidewall, see "Tire
size designation, load and speed rating"
(

page 196)
.
If you are uncertain about the correct read

ing of the information given on a tire’s side

wall, any authorized smart center will be glad
to assist you.i
For information on speed ratings for
winter tires, see "All
season and winter tires
"
(

page 199).
For additional general information on tire
speed markings on tire sidewall, see "Tire
speed rating" (

page 198).
Winter driving instructionsThe most important rule for slippery or icy
roads is to drive sensibly and to avoid abrupt
acceleration, braking and steering maneu

vers.
When the vehicle is in danger of skidding,
move gear selector lever to neutral
positionN. Try to keep the vehicle under
control by corrective steering action.
For information on driving with snow chains*,
see "Snow chains*" (

page 209).
G
Warning!
Even when permitted by law, never oper

ate 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.
G
Warning!
On slippery road surfaces, never down

shift in order to obtain braking action.
This could result in drive wheel slip and
reduced vehicle control. Your vehicle’s
ABS will not prevent this type of loss of
control.