2006 BMW Z4 COUPE wheel

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59
Air distribution
Direct the flow of air to the windows
, to the upper body area and to
the footwell . Intermediate settings
are possible.
Switching cooling function on/off
When the cooling function is on, the
air is cooled, dehumidified, then
reheated depending on the tempera-
ture setting.
Depending on the weather, the windshield may
fog over briefly when the engine is started.
Recirculated-air mode
If the air outside the car has an
unpleasant odor or contains pollut-
ants, temporarily shut off the supply
to the interior of the car. The system
recirculates the air within the vehicle.
If the windows fog over in the recircu-
lated-air mode, you should switch it off
and, if necessary, increase the air flow rate.
The manually controlled recirculated-air mode
should not be used continuously for lengthy
periods, otherwise the quality of the air inside
the car will gradually deteriorate.<
Temperature
For a higher temperature, turn the
rotary switch clockwise towards red.
For a lower temperature, turn the
rotary switch counterclockwise
towards blue.
Air flow rate
Adjust the air flow rate. The higher
the rate, the more effective the heat-
ing or cooling will be.
Switching the system on/off
Set the air flow rate to 0. Blower and air condi-
tioning are switched off and the air supply is cut
off.
To switch on the heater or air conditioning, set
any desired air flow rate.
Rear window defroster
The defroster switches off automati-
cally after a certain time.
Defrosting windows and removing
condensation
1.Air distribution1 in position .
2.Set air flow rate 2 to position 4.
3.Temperature3 to the right, red.
4.Switch on rear window defroster 4 to
defrost the rear window.
Ventilation
1Knurled wheels to set any vent position
from fully open to closed
2Slide for adjusting air flow direction
Ventilation for cooling
Adjust the vent outlets to direct the flow of cool
air toward you, for instance if it has become too
hot in the car.
Draft-free ventilation
Set the vent outlets so that the air flows past
you and not straight at you.

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Mobility
63
automatic climate control does not have
enough time to achieve the set temperature.<
AUC Automatic recirculated-air
control/Recirculated-air mode
Switch on the desired operating
mode by pressing this button repeat-
edly:
>LEDs off: outside air flows in continuously.
>Left-hand LED on, AUC mode: a sensor
detects pollutants in the outside air. If nec-
essary, the system blocks the supply of out-
side air and recirculates the inside air. As
soon as the concentration of pollutants in
the outside air has decreased sufficiently,
the system automatically switches back to
outside air supply.
>Right-hand LED on, recirculated-air mode:
the inflow of outside air is shut off perma-
nently. The system recirculates the air
within the vehicle.
If the windows fog over in the recircu-
lated-air mode, you should switch it off
and, if necessary, increase the air flow rate.
The recirculated-air mode should not be used
over an extended period of time, otherwise the
air quality inside the car will deteriorate contin-
uously.<
Rear window defroster
The defroster switches off automati-
cally after a certain time.
Ventilation
1Knurled wheels to set any vent position
from fully open to closed
2Slide for adjusting air flow direction
Ventilation for cooling
Adjust the vent outlets to direct the flow of cool
air toward you, for instance if it has become too
hot in the car.
Draft-free ventilation
Set the vent outlets so that the air flows past
you and not straight at you.
Microfilter/activated-charcoal filter
The microfilter removes dust and pollen from
the incoming air. The activated-charcoal filter
provides additional protection by filtering gas-
eous pollutants from the outside air. Your BMW
Center replaces this combined filter during reg-
ular maintenance. A substantial reduction in air
flow indicates that the filter needs to be
replaced earlier.

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

Wheels and tires
80
Wheels and tires
Tire inflation pressure
Information for your safety
It is not merely the tire's service life, but also
driving safety and driving comfort that largely
depend on the condition of the tires and the
maintenance of the specified tire pressure.
Check tire inflation pressures regularly
and correct them if necessary: at least
every two weeks and before every extended
journey. If you fail to observe this precaution
you may be driving on tires with incorrect tire
pressures, a condition that can not only com-
promise your vehicle's driving stability, but also
lead to tire damage 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 seri-
ously 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
Check the tire inflation pressures only 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. Warm tires
have higher inflation pressures.
Inflation pressure specifications
The specified inflation pressures for your stan-
dard tires are provided on the placard on the
B-pillar and are visible when the driver's door is
open.Reinitialize the Flat Tire Monitor after cor-
recting the tire inflation pressure. Refer to
page51.<
The following tire inflation pressure tables show
the inflation pressures for the specified tire
sizes at ambient temperature.
The inflation pressures in the table apply
to BMW-approved tire sizes and recom-
mended tire brands. Your BMW Center will be
glad to supply this information.<
To determine the correct tire inflation pressure
for your tires, refer to the following tables.
Tire size
The inflation pressures in the table apply to
BMW-approved tire sizes and recommended
tire brands. Your BMW Center will be glad to
supply this information.

Wheels and tires
82
Z4 Coupe 3.0si
Tire coding
Understanding the lettering on the tire sidewall
makes it easier to identify and choose the cor-
rect tires.
Tire size
Speed code letter
Q = up to 100mph or 160km/h
T = up to 118mph or 190km/h
H = up to 131mph or 210km/h
V = up to 150mph or 240km/h
W = up to 167mph or 270km/h
Y = up to 186mph or 300km/h
Tire Identification Number
Tires with DOT codes meet the guidelines of
the U.S. Department of Transportation.DOT code:
Tire age
The date on which the tire was manufactured is
indicated by the code on the sidewall:
DOT … 5005 indicates that the tire was manu-
factured in week 50 of the year 2005.
BMW recommends the replacement of all tires
every 6 years at the latest, even if a tire usage of
10 years is possible.
Uniform Tire Quality Grading
Quality grades can be found where applicable
on the tire sidewall between tread shoulder and
maximum section width. For example:
Treadwear 200 Traction AA
Temperature A
DOT Quality Grades
Tread wear
Traction AA A B C
Temperature A B C
Tire sizePressure specifications in psi/kPa
All pressure specifications in the table are
indicated in psi/kilopascal with cold tires,
cold = ambient temperature
225/45 R 17 91 W
225/45 R 17 91 H/V M+S33/230 39/270
Front: 225/45 R 17 91W
Rear: 255/40 R 17 94 W33/230
––
39/270
Front: 225/40 R 18 88 W
Rear: 255/35 R 18 90 W33/230
––
39/270
You will find more information about permissible loads and weights on page109.
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 tires225/50 R1692 V
e.g.
Manufacturer's code
for tire make
Tire size and
tire design
Tire ageDOT xxxx xxx 5005

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All passenger car tires must conform to
Federal Safety Requirements 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 conditions 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 govern-
ment course as a tire graded 100. The relative
performance of tires depends upon the actual
conditions of their use, however, and may
depart significantly from the norm due to varia-
tions in driving habits, service practices and dif-
ferences in road characteristics 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-ahead braking traction
tests, and does not include acceleration, cor-
nering, hydroplaning, or peak traction charac-
teristics.<
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 wheel 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 excessive loading, either sep-
arately or in combination, can cause heat
buildup and possible tire failure.<
RSC: Run-Flat Tires
Run-Flat tires are labeled on the sidewall with a
circular symbol containing the letters RSC.
Refer to page84.
M+S
Winter and all-season tires.
These have better winter performance proper-
ties than summer 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/
3 mm, although, for example, 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 should be installed.
Wear indicators in the base of the tread groove
are distributed around the tire's circumference;

Wheels and tires
84 the letters TWI, for Tread Wear Indicator, on the
tire's sidewalls identify tires that incorporate
these wear indicators. Once 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
Due to low-profile tires, please note that
wheels, tires and suspension parts are
more susceptible to road hazards and conse-
quential damages.<
Unusual vibrations encountered during normal
vehicle operation can indicate tire failure or
some other vehicle malfunction. This can, for
example, 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.
Tire damage can be extremely dangerous for
vehicle occupants and other road users.<
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 date on which the tire was manufactured is
indicated by the code on the sidewall:
DOT … 5005 indicates that the tire was manu-
factured in week 50 of the year 2005.
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 subject to certain restric-
tions, even if depressurized.
For information on continuing to drive with a flat
tire, refer to Flat tire warning on page51.
Wheel and tire replacement
Have new wheels and tires installed only
by your BMW Center or tire shop that
works according to BMW repair procedures
with correspondingly trained personnel. Work
that is improperly carried out could result in
consequential damage and pose safety haz-
ards. Make sure that the new wheels are bal-
anced.<
Retreaded tires
BMW advises against using retreaded
tires, since driving safety may be
impaired. The causes for this include potentially
different tire casing structures and often wide
variations in tire age, which can result in a lim-
ited service life.<
Correct wheels and tires
BMW recommends using only wheels
and tires that have been approved by
BMW for your particular vehicle model, other-
wise body contact and serious accidents can
result despite the use of the same nominal size,
e.g. due to manufacturing tolerances. If non-

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approved wheels and tires are used, BMW can-
not evaluate their suitability, and therefore can-
not be held liable for driving safety.<
You can inquire about the correct wheel/tire
combination 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 and DSC.
To maintain good handling and vehicle
response, only use tires of a single brand and
tread configuration. After a tire has been dam-
aged, for instance, mount the original wheel and
tire combination again as soon as possible.
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.
Run-Flat 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, moreover, no spare wheel is
available. Your BMW Center will be glad to pro-
vide you with more information.
For safety reasons, BMW recommends
that damaged Run-Flat Tires be replaced
rather than repaired.<
Special characteristics of winter tires
BMW recommends the use of winter tires for
operation under winter road conditions. While all-season tires with M+S designation provide
better winter traction than summer tires, they
generally do not achieve the full performance of
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 tires, 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
Store tires in a cool, dry place, protecting them
against light whenever possible. Protect the
tires from contact with oil, grease and fuel. Do
not exceed the maximum tire inflation pressure
indicated on the sidewall of the tire.
Snow chains*
Only certain fine-link snow chains have been
tested by BMW, classified as safe for use and
recommended. Consult your BMW Center for
more information. Attach snow chains in pairs
and only to the rear wheels.
Observe the manufacturer's instructions when
mounting snow chains. Do not exceed a speed
of 30 mph/50 km/h when using snow chains.
You are not permitted to mount snow chains to
tires of the following sizes:
>255/40 R 17
>255/35 R 18
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
page50.<