2009 BMW Z4 SDRIVE30I ROADSTER tire size

Technology for driving comfort and safety
84
2.
In the event of complete pressure loss,
0 psi/0 kPa, you can estimate the possible
distance for continued driving on the basis
of the following guidelines:
>With a light load:
1 person without luggage:
approx. 155 miles/250 km
> With a medium load:
1 person, cargo bay full, or 2 people
without luggage:
approx. 95 miles/150 km
> With a full load:
2 people, cargo bay full:
approx. 30 miles/50 km
Drive cautiously and do not exceed a
speed of 50 mph/80 km/h. In the event of
pressure loss, vehicle handling changes. This
includes reduced tracking stability in braking,
extended braking distance and altered natural
steering characteristics.
If unusual vibration or lo ud noises occur during
the journey, this may be an indication that the
damaged tire has finally failed. Reduce your
speed and pull over as soon as possible at a
suitable location. Otherw ise parts of the tire
could come loose, resulting in an accident. Do
not continue driving. Instead, contact your
BMW center. <
Message for unsuccessful system
reset
The warning lamp lights up yellow. A
message will appear on the Control
Display. The system is not reset after
a tire has been changed, for example.
Check the tire inflation pressure and reset the
system, refer to page 83.
Status display
iDrive, for operating pr inciple refer to page16.
1. Press the button
The start menu is opened.
2. "Vehicle Info"
3. "Vehicle status"
4. "TPM"
5. The status is displayed.
Malfunction
The small warning lamp flashes in
yellow and then lights up continu-
ously; the larger warning lamp comes
on in yellow. On the Control Display,
the tires are shown in gray and a message
appears. No punctures can be detected.
This type of message is shown in the following
situations:
> If there is a malfunction
Have the system checked.
> If a wheel without TPM electronics has
been mounted
> If TPM is temporarily malfunctioning due to
other systems or devices using the same
radio frequency.
Declaration according to
NHTSA/FMVSS 138
Tire Pressure Monitoring Systems
Each tire should be checked monthly when cold
and inflated to the inflation pressure recom-
mended by the vehicle manufacturer on the
vehicle placard or tire infl ation pressure label. If
your vehicle has tires of a different size than the
size indicated on the vehicle placard or tire infla-
tion pressure label, yo u should determine the
proper tire inflation pressure for those tires. As
an added safety feature, your vehicle has been
equipped with a tire pressure monitoring sys-
tem, TPMS, that illuminates a low tire pressure
telltale when one or more of your tires are signif-
icantly under-inflated. Accordingly, when the
low tire pressure telltale illuminates, you should
stop and check your tires as soon as possible,
and inflate them to the proper pressure. Driving
on a significantly underi nflated tire causes the
tire to overheat and ca n lead to tire failure.
Underinflation also reduces fuel efficiency and
tire tread life, and may affect the vehicle’s han-
dling and stopping ability. Please note that the
TPMS is not a substitute for proper tire mainte-
nance, and it is the dr iver’s responsibility to
maintain correct tire pressure, even if underin-
flation has not reached the level at which the
TPMS low tire pressure telltale illuminates.

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After mounting a child seat, ensure that the
indicator lamp for the pa ssenger airbag is lit.
It indicates that the child seat has been
detected and that th e passenger airbags
are deactivated.
> The indicator lamp does not come on as
long as a person of sufficient size and in a
correct sitting position is detected on
the seat.
The front, knee and passenger airbags for
the passenger are activated.
Operational readiness of airbag system
As of radio readiness, refer to page 50, the
warning lamp comes on br iefly to indicate that
the entire airbag system and the belt tensioners
are operational.
Airbag system malfunction
> Warning lamp does not light up at radio
readiness or beyond.
> Warning lamp remains permanently on.
In the event of a fault in the airbag system,
have it checked without delay, otherwise
there is the risk that th e system will not function
as intended even if a sufficiently severe acci-
dent occurs. <

Wheels and tires
190
Wheels and tires
Tire inflation pressures
Information for your safety
It is not merely the tires' service life, but also
driving comfort and, to a great extent, driving
safety that depend on the condition of the tires
and the maintenance of the specified tire
pressure.
Check the tire inflatio n pressure regularly
and correct it, if necessary: at least twice a
month and before starting long trips. If you fail
to observe this precaution you may be driving
on tires with incorrect tire pressures, a condi-
tion that can not only compromise your vehi-
cle's driving stability, but also lead to tire dam-
age and the risk of an accident. Do not drive
with deflated, i.e. flat tires, except when using
Run-Flat Tires. A flat tire will seriously impair
your vehicle's handling and braking response.
Attempts to drive on a flat tire can lead to loss of
control over the vehicle.<
Checking pressure
Only check tire inflation pressure when the
tires are cold. This means after a maximum of
1.25 miles/2 km driving or when the vehicle has
been parked for at least 2 hours. When tires are
warm, the tire inflatio n pressure is higher.
After correcting the tire inflation pressure,
reinitialize the Tire Pressure Monitor,
refer to page 83, or the Flat Tire Monitor, refer
to page 81.<
Inflation pressure specifications
The tables below provide all the correct inflation
pressures for the specified tire sizes at ambient
temperature.
The inflation pressures apply to the tire
sizes approved and tire brands recom-
mended by BMW; a list of these is available
from your BMW center. <
For correct identification of the right tire infla-
tion pressures, observe the following: >
Tire sizes for your vehicle
> Load conditions
> Maximum allowable driving speed
Tire inflation pressures for driving up to
100 mph or 160 km/h
For normal driving up to 100 mph or 160 km/h
and to achieve optimum driving comfort, adjust
pressures to the respecti ve tire inflation pres-
sures listed on the follo wing pages in the col-
umns for traveling speeds up to a maximum of
100 mph or 160 km/h.
These tire inflation pre ssures can also be found
on the driver's-side door post when the driver's
door is open.
The maximum permissible speed for
these tire pressures is 100 mph or
160 km/h. Do not exceed this speed, otherwise
tire damage and accidents could occur. <
Tire inflation pressures for driving
above 100 mph or 160 km/h
In order to drive at maximum speeds in
excess of 100 mph or 160 km/h, adjust
pressures to the respecti ve tire inflation pres-
sures listed on the follo wing pages in the col-
umns for traveling speeds including those
exceeding 100 mph or 160 km/h. Otherwise tire
damage and accidents could occur. <

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Observe all national and local maximum speed
limits, otherwise violations of the laws could
occur.
Tire inflation pre ssures Z4 sDrive30i
Tire size Pressure specificat ions in psi/kPa
Traveling speeds up to a max. of
100 mph / 160 km/h Traveling speeds
including those exceeding 100 mph / 160 km/h
All pressure specifications in
the table are indicated in
psi/kilopascal with cold tires.
Cold = ambient temperature
without Sports package:
225/45 R 17 91 V
225/45 R 17 91 H M+S
225/45 R 17 94 V M+S XL 36/250 44/300
36/250 44/300
Front: 225/45 R 17 91 V 36/250 -36/250-
Rear: 255/40 R 17 94 V - 39/270-39/270
Front: 225/40 R 18 88 W 36/250 -36/250-
Rear: 255/35 R 18 90 W - 42/290-42/290
Front: 225/35 R 19 88 Y XL 36/250 - 36/250-
Rear: 255/30 R 19 91 Y XL - 42/290-42/290
with Sports package:
225/45 R 17 91 W
225/45 R 17 91 H M+S
225/45 R 17 94 V M+S XL 36/250 44/300
36/250 44/300
Front: 225/45 R 17 91 W 36/250 -36/250-
Rear: 255/40 R 17 94 W - 39/270 - 39/270
Front: 225/40 R 18 88 W 36/250 -38/260-
Rear: 255/35 R 18 90 W - 42/290-45/310
Front: 225/35 R 19 88 Y XL 36/250 - 36/250-
Rear: 255/30 R 19 91 Y XL - 42/290-44/300
More details on the permissible load and weights can be found on page222.

Wheels and tires
192
Tire inflation pressures Z4 sDrive35i
Tire size Pressure specifications in psi/kPa
Traveling speeds up to a max. of
100 mph / 160 km/h Traveling speeds
including those exceeding 100 mph / 160 km/h
All pressure specifications in
the table are indicated in
psi/kilopascal with cold tires.
Cold = ambient temperature
without Sports package:
225/45 R 17 91 H M+S
225/45 R 17 94 V M+S XL 36/250 44/300
36/250 44/300
Front: 225/45 R 17 91 V 36/250 -36/250-
Rear: 255/40 R 17 94 V - 39/270-39/270
Front: 225/40 R 18 88 W 36/250 -36/250-
Rear: 255/35 R 18 90 W - 49/270-42/290
Front: 225/35 R 19 88 Y XL 36/250 - 36/250-
Rear: 255/30 R 19 91 Y XL - 42/290-42/290
with Sports package:
225/45 R 17 91 H M+S
225/45 R 17 94 V M+S XL 36/250 44/300
36/250 44/300
Front: 225/45 R 17 91W 36/250 -36/250-
Rear: 255/40 R 17 94 W - 39/270 - 39/270
Front: 225/40 R 18 88 W 36/250 -38/260-
Rear: 255/35 R 18 90 W - 42/290-45/310
Front: 225/35 R 19 88 Y XL 36/250 - 36/250-
Rear: 255/30 R 19 91 Y XL - 42/290-44/300
More details on the permissible load and weights can be found on page222.

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Tire identification marks
Knowledge of the labeling on the side of the tire
makes it easier to identify and choose the right
tires.
Tire size
Speed code letter
Q = up to 100 mph or 160 km/h
T = up to 118 mph or 190 km/h
H = up to 131 mph or 210 km/h
V = up to 150 mph or 240 km/h
W = up to 167 mph or 270 km/h
Y = up to 186 mph or 300 km/h
Tire Identification Number
Tires with DOT codes meet the guidelines of
the US Department of Transportation.
DOT code:
Tire age
The manufacturing date of tires is contained in
the tire coding: DOT … 0709 means that the
tire was manufactured in week 7 of 2009.
BMW recommends that you replace all tires
after 6 years at most, even if some tires may last
for 10 years.
Uniform Tire Quality Grading
Quality grades can be found where applicable
on the tire sidewall between tread shoulder and
maximum section width. For example:
Tread wear 200 Traction AA
Temperature A
DOT Quality Grades
Tread wear
Traction AA A B C
Temperature A B C
All passenger car tires must conform to
Federal Safety Requir ements in addition
to these grades. <
Tread wear
The tread wear grade is a comparative rating
based on the wear rate of the tire when tested
under controlled conditio ns on a specified gov-
ernment test course. For example, a tire graded
150 would wear one and one-half (1 γ) times as
well on the government course as a tire graded
100. The relative performance of tires depends
upon the actual conditions of their use, how-
ever, and may depart significantly from the
norm due to variations in driving habits, service
practices and differences in road characteris-
tics and climate.
Traction
The traction grades, from highest to lowest, are
AA, A, B, and C.
Those grades represent the tire's ability to stop
on wet pavement as measured under controlled
conditions on specified government test sur-
faces of asphalt and concrete. A tire marked C
may have poor traction performance.
The traction grade assigned to this tire is
based on straight-ahe ad braking traction
tests, and does not in clude acceleration, cor-
nering, hydroplaning, or peak traction charac-
teristics. <
e.g.
Nominal width in mm
Aspect ratio in Ξ
Radial belt construction
Rim diameter in inches
Load rating,
not on ZR tires
Speed code letter, in
front of the R on ZR tires225/45 R1791 V
e.g.
Manufacturer's code
for tire make
Tire size and
tire design
Tire ageDOT xxxx xxx 0709

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Tire age
For various reasons, such as the development
of brittleness, BMW recommends tire replace-
ment after no more than 6 years, regardless of
the actual wear of the tires.
The manufacturing date of tires is contained in
the tire coding:
DOT ... 0709 means that the tire was manufac-
tured in week 7 of 2009.
Run-Flat Tires
The symbol identifying Run-Flat Tires is a circle
with the letters RSC on the sidewall.
Run-Flat Tires comprise a conditionally self-
supporting tire and a special rim. The reinforce-
ment in the sidewalls ensures that the tire can
continue to be used su bject to certain restric-
tions, even if depressurized.
For information on continuing to drive with a flat
tire, refer to Indication of a flat tire, page 81.
New wheels and tires
Have new wheels and tires installed only
by your BMW center or tire shop that
works according to BMW repair procedures
with correspondingly trai ned personnel. If this
work is not carried out properly, there is a dan-
ger of subsequent dama ge and related safety
hazards. Make sure that the new wheels are bal-
anced. <
Retreaded tires
BMW recommends that you do not use
retreaded tires, since driving safety may
be impaired. The causes for this include poten-
tially different tire casi ng structures and often
wide variations in tire ag e, which can result in a
limited service life. <
Correct wheels and tires
When mounting new tires or changing over
from summer to winter tires and vice versa,
mount Run-Flat Tires for your own safety. In the
event of a flat, no spare wheel is available. Your
BMW center will be glad to advise you.
BMW recommends that you use only
wheel and tire combinations that BMW
has tested and approved for your particular
vehicle. Variations in factors such as manufac-
turing tolerances mean that even wheels and
tires with identical official size ratings could
actually have different dimensions, which could
lead to body contact and thus to severe acci-
dents. If non-approved wheels and tires are
used, BMW cannot evaluate their suitability,
and therefore cannot guarantee their driving
safety. <
You can inquire about the right wheel/tire com-
bination at your BMW center.
The correct combination of wheels and tires is
also necessary to ensure reliable operation of
various vehicle systems such as ABS, DSC
or TPM.
To maintain good handling and vehicle
response, use only tires of a single brand and
tread configuration. After a tire has been dam-
aged, mount the previous wheel and tire combi-
nation again as soon as possible.
Wheels with Tire Pressure Monitor
TPM electronics
When mounting new tires or changing over
from summer to winter tires, or vice versa, only
use wheels with TPM electronics; otherwise the
Tire Pressure Monitor may not be able to detect
a puncture, refer to page 82. Your BMW center
will be glad to advise you.

Wheels and tires
196
Recommended tire brands
Certain makes of tire are recommended by
BMW for each tire size. They are marked with a
clearly visible BMW designation on the sidewall
of the tire.
When properly used, these tires meet the high-
est standards in terms of safety and handling
characteristics.
Special characteristics of winter tires
BMW recommends winter tires for winter roads
or at temperatures below +45 7/+7 6.
Although all-season M+ S tires provide better
winter traction than summer tires, they gener-
ally fail to provide the same levels of cold-
weather performance as winter tires.
Pay attention to speed
Always comply with the speed limit for the
winter tires mounted on your car; failure
to do so could result in tire damage and acci-
dents. <
If the car is capable of speeds higher than that
permitted for the winter ti res, a label stating the
maximum permitted speed for the mounted
tires must be displayed in your field of view.
Specialist tire dealers and your BMW center
can supply these labels.
Storage
Always store wheels and tires in a cool, dry
place with as little exposure to light as possible.
Always protect tires agains t all contact with oil,
grease and fuels. Do not exceed the maximum
tire inflation pressure indicated on the sidewall
of the tire.
Swapping wheels between axles
BMW advises against swapping wheels
between the front and rear axles, even if all tires
have the same size, as th is could impair driving
characteristics. If the tires are of mixed sizes,
swapping wheels betwee n the axles is not per-
missible.
Snow chains*
Only certain fine-link sn ow chains have been
tested by BMW, classified as safe for use and
recommended. Consult your BMW center for
more information.
Snow chains must be mounted in pairs and on
the rear wheels only. Observe the manufac-
turer's instructions when mounting snow
chains. Do not exceed a speed of 30 mph or
50 km/h.
Do not initialize the Flat Tire Monitor if
snow chains are mounted, otherwise the
instrument might issue an incorrect reading.
When driving with snow chains, you may find it
helpful to activate DTC temporarily, refer to
page 78.<