2009 BMW Z4 SDRIVE30I tires

Driving tips
113Reference
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Before driving into a car wash
General information on caring for your BMW
can be found on page204.
With convenient access and automatic
transmission
Insert the remote control into the ignition
switch.
The engine can be switched off when the selec-
tor lever is in position N. Refer also to page 204.
With convenient access and 7-gear
sport automatic transm ission with dual
clutch
Insert the remote control into the ignition
switch.
The engine can be switched off when the trans-
mission is in position N. Refer also to page 205.
Cargo loading
To avoid loading the tires beyond their
approved carrying capacity, never over-
load the vehicle. Overlo ading can lead to over-
heating and increases the rate at which damage
develops inside the tires. This can ultimately
result in a sudden blow-out. <
Make sure that no liquids are spilled or
leak from their containers in the cargo
bay, as this could result in damage to the
vehicle. <
When storing objects in the rear storage
shelf, do not move both seats all the way
forward while moving th em to their uppermost
position and leaning the backrests forward.
Otherwise, the seats could hit and damage the
seal on the windshield, the sun visor and the
headliner. <
Determining loading limit
1.Locate the following statement on your
vehicle's placard
*:
The combined weight of occupants
and cargo should never exceed
XXX kg or YYY lbs. Otherwise, overloading
can result in damage to the vehicle and
unstable driving conditions.<
2. Determine the combined weight of the
driver and passengers that will be riding in
your vehicle.
3. Subtract the combined weight of the driver
and passengers from XXX kilograms or YYY
pounds.
4. The resulting figure equals the available
amount of cargo and luggage load capacity.
For example, if the YYY amount equals
1,400 lbs. and there will be five 150-lb.
passengers in your ve hicle, the amount of
available cargo and lugga ge load capacity is
650 lbs:
1,400 lbs. minus 750 lbs. = 650 lbs.
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.
6. If your vehicle will be towing a trailer, part of
the load from your tra iler will be transferred
to your vehicle. Consult the manual for
transporting a trailer to determine how this
may reduce the availa ble cargo and luggage
load capacity of your vehicle.

Mobility
This section helps you maintain your car's
mobility by supplying important information
on vital topics including fuels and lubricants,
wheels and tires, serv ice, maintenance and
breakdown assistance.
Mobility

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. <

Mobility
191Reference
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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.

Mobility
193Reference
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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

Wheels and tires
194
Temperature
The temperature grades are A, the highest, B,
and C, representing the tire's resistance to the
generation of heat and its ability to dissipate
heat when tested under controlled conditions
on a specified indoor laboratory test wheel.
Sustained high temperature can cause the
material of the tire to degenerate and reduce
tire life, and excessive temperature can lead to
sudden tire failure. The grade C corresponds to
a level of performance which all passenger car
tires must meet under the Federal Motor Vehi-
cle Safety Standard No. 109. Grades B and A
represent higher levels of performance on the
laboratory test whee l than the minimum
required by law.
The temperature grade for this tire is
established for a tire that is properly
inflated and not overloaded. Excessive speed,
underinflation, or excessi ve loading, either sep-
arately or in combination, can cause heat
buildup and possible tire failure. <
RSC – Run-Flat Tires
You will recognize Run-Flat Tires by a circular
symbol containing the letters RSC on the side
of the tire, refer to page195.
M+S
Winter and all-season tires.
These have better winter properties than sum-
mer tires.
XL
Designation for specia lly reinforced tires.
Tire condition
Inspect your tires frequently for tread wear,
signs of damage and for foreign objects lodged
in the tread. Check the tread depth.
Minimum tread depth
The tread depth should not drop below 1/8 in/
3mm, although, for exam ple, European legisla-
tion only specifies a minimum tread depth of 1/16 in/1.6 mm. At tread depths below 1/8 in/
3 mm there is an increased risk of high-speed
hydroplaning, even when only small amounts of
water are present on the road surface.
When winter tires wear down past a tread depth
of 1/6 in/4 mm, they become perceptibly less
suitable for winter conditions. In the interest of
safety, new tires sh
ould be installed.
Wear indicators in the ba se of the tread groove
are distributed around th e tire's circumference;
the letters TWI, for Tread Wear Indicator, on the
tire's sidewalls identify tires that incorporate
these wear indicators. On ce the tire tread has
worn down to the wear indicators, the tire has
worn to a depth of 1/16 in/1.6 mm.
Wheel/tire damage
Please note that low-pr ofile tires cause wheels,
tires and suspension parts to be more suscep-
tible to road hazard and consequential
damages.
Unusual vibrations encountered during normal
vehicle operation can indi cate tire failure or
some other vehicle defect. This can, for exam-
ple, be caused by driving over curbs. The same
applies to any other abnormal road behavior,
such as pulling severely to the right or left.
In these cases, reduce speed immedi-
ately and have wheels and tires thor-
oughly checked. To do so, drive carefully to the
nearest BMW center or tire shop that works
according to BMW repair procedures with cor-
respondingly trained personnel. If necessary,
have the vehicle towed there.
Otherwise, tire damage can be extremely dan-
gerous for vehicle occu pants and other road
users. <

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195Reference
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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.