2004 BMW Z4 ROADSTER 3.0I ESP

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63
Outside air/Automatic recirculated
air control AUC/recirculated air
mode
You can respond to unpleasant
external odors or pollutants by
temporarily stopping the flow of
outside air. The system then
recirculates the air currently within the
vehicle.
By repeatedly pressing the button, you can
select one of three different operating
modes.
>Indicator lamps off: outside air flows
into the vehicle
>Left-hand indicator lamp on, AUC
mode: the system detects pollutants in
the outside air and responds by deacti-
vating the outside airflow as required.
The system then recirculates the air
currently within the vehicle. Depending
on air quality requirements, the system
automatically switches between out-
side air supply and recirculation of the
air already within the vehicle
>Right-hand indicator lamp on: the flow
of outside air is permanently blocked.
The system recirculates the air already
within the vehicle.
If the windows fog over in the recircu-
lated air mode, switch this mode off
and increase the air supply as required. Do
not use the recirculated-air mode continu-
ously over a long period of time as this
would reduce the air quality in the interior
of the vehicle.<
Rear window defroster
The indicator lamp lights up when
the rear window defroster is
active. The rear window defroster
switches off automatically.
Ventilation
You can adjust the blower controls for the
upper body area to obtain the optimum air-
flow rates and directions for your personal
requirements:
1Rotary dials for opening and closing the
vents at any setting desired
2Sliders for adjusting airflow direction
Microfilter/activated-charcoal filter
The built-in microfilter removes dust and
pollen from the incoming air. The activated-
charcoal filter provides additional protec-
tion by filtering gaseous pollutants from the
outside air. Your BMW center replaces this
combined filter as a standard part of your
scheduled maintenance. A substantial
reduction in airflow indicates that the filter
needs to be replaced earlier.

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Driving notes
Parking the vehicle
Condensation forms in the air conditioner
system during operation, which then exits
under the vehicle. Traces of condensed
water on the ground underneath the vehi-
cle are thus normal.
Brakes
Do not drive with your foot resting on
the brake pedal. Even light but con-
sistent pedal pressure can lead to high
temperatures, brake wear and possibly
even brake failure.
Hydroplaning
When driving on wet or slushy roads,
reduce vehicle speed. If you do not, a
wedge of water may form between the tires
and the road surface. This phenomenon
can lead to partial or complete loss of trac-
tion, vehicle control and braking effective-
ness.<
Driving through water
Do not drive through water on the
road if it is deeper than 1 ft / 30 cm,
and then only at walking speed. Otherwise,
the vehicle's engine, the electrical systems
and the transmission may be damaged.<
High temperatures
High temperatures occur with every
vehicle equipped with a catalytic con-
verter. Heat shields are installed adjacent
to some sections of the exhaust system.
Never remove these shields; do not apply
undercoating to their surfaces. When driv-
ing, standing at idle and parking the vehi-
cle, take care to avoid contact between the
hot exhaust system and flammable materi-
als, e.g. hay, leaves, grass, etc. Such con-
tact could lead to a fire, resulting in serious
personal injury and property damage.<
Brake system
Indicator lamp
The indicator lamp lights up
although the parking brake is not
engaged:
Check the brake fluid level. It is very impor-
tant that you follow the instructions on
page 85 before driving on.
Disc brakes
Corrosion
Limited vehicle use, extended periods with
the vehicle parked or in storage, and oper-
ating conditions in which braking is
restricted to gentle, low-pressure applica-
tions will all increase the tendency for cor-
rosion to form on the rotors and contamina-
tion to accumulate on the brake pads. This
occurs because the minimal pressure
which must be exerted by the pads to clean
the rotors by brake applications is not
reached.
If the brake rotors are corroded, they will
tend to respond to braking with a pulsating
effect which even extended application will
fail to cure.
Wet roads
When driving in heavy rain and on wet
roads, it is useful to apply light pressure
to the brake pedal every few miles. Watch
traffic conditions to ensure that this maneu-
ver does not endanger other road users.
The resulting heat dries the brake rotors
and brake pads. Immediate braking control
is then available if necessary.
Inclines
Extended or steep mountain descents
should be driven in the gear or drive posi-
tion in which only minimal periodic brake
application is required. This helps avoid
placing excessive loads on the brake sys-
tem. Observe the maximum allowable
engine speed when doing so; refer to
page 48.

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Wheels and tires
Tire inflation pressure
Information for your safety
It is not merely the tire's service life, but
also driving comfort and driving safety that
largely depend on the condition of the tires
and the maintenance of the specified tire
pressure.
Check tire inflation pressures regu-
larly and correct them if necessary: at
least every two weeks and before every
extended journey. If this is not done, incor-
rect tire pressures can cause driving insta-
bility or tire damage, ultimately resulting in
accidents.
Do not drive with a deflated, i.e. flat, tire
unless your vehicle is equipped with Run
Flat tires. A flat tire greatly impairs steering
and braking response, and can lead to
complete loss of control over the vehicle.<
Checking tire pressures
Check the tire inflation pressures only
when the tires are cold. This means after a
maximum driving distance of 1.25 miles/
2 km or if the vehicle has been parked for at
least 2 hours. Warm tires have higher infla-
tion pressures.
Reinitialize the Flat Tire Monitor after cor-
recting the tire inflation pressure. Refer to
page 55.
Inflation pressures for original tires
The specified inflation pressures for tires at
ambient temperature are provided on the
placard on the B-pillar and are visible when
the driver's door is open.
Inflation pressures for other tire
sizes
The following tire inflation pressure tables
show the inflation pressures for the speci-
fied tire sizes at ambient temperature.
Reinitialize the Flat Tire Monitor after
correcting the tire inflation pressure.
Refer to page 55.<
Tire size
The inflation pressures in the table apply to
BMW-approved tire sizes and brands. Your
BMW center will be glad to supply this
information.

Wheels and tires
76
Z4 2.5i
Z4 3.0i
TiresPressure specifications in psi/kPa
Tires
All pressure specifications in the table are
indicated in psi/kilopascal with cold tires,
cold = ambient temperature
225/50 R 16 92 V
225/45 R 17 91 W30/210 33/230
225/40 R 18 88 W 30/210 –
245/40 R 17 91 W
255/35 R 18 90 W–33/230
All winter tires 30/210 33/230
You will find more information about permissible loads and weights on page 101.
TiresPressure specifications in psi/kPa
Tires
All pressure specifications in the table are
indicated in psi/kilopascal with cold tires,
cold = ambient temperature
225/45 R 17 91 W 33/230 36/250
225/40 R 18 88 W 33/230 –
245/40 R 17 91 W
255/35 R 18 90 W–36/250
All winter tires 33/230 36/250
You will find more information about permissible loads and weights on page 101.

Wheels and tires
78
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 con-
trolled conditions on a specified indoor lab-
oratory 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 Vehicle Safety
Standard No. 109. Grades B and A repre-
sent 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, under-inflation, or excessive load-
ing, either separately 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 page 80.
M+S
Winter and all-season tires.
These have better winter performance
properties 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.
Tire tread
Tread depth should not be allowed to go
below 1/8 in/3 mm even though in Europe,
for example, the legally specified minimum
tread depth is only 1/16 in/1.6 mm. Below
1/8 in/3 mm tread depth, there is a very
high risk of hydroplaning, even at relatively moderate speeds and with only small
amounts of water on the road.
At tread depths below approx. 1/6 in/
4 mm, winter tires display a perceptible
decrease in their ability to cope with winter
driving conditions, and should be replaced
in the interest of safety.
Tread wear indicators in the tread-groove
base, see arrow, are distributed around the
wheel circumference and are labeled on
the tire sidewall as TWI, Tread Wear Indica-
tor. At a tread depth of 1/16 in/1.6 mm, the
indicators signal that the legally permissi-
ble wear limit has been reached.
Tire damage
Unusual vibrations encountered dur-
ing normal vehicle operation can indi-
cate tire failure or some other vehicle mal-
function. This type of problem can be
caused by contact with curbs, etc. This is
also true for irregularities in the vehicle's
handling characteristics, such as a pro-
nounced tendency to pull to the left or right.
Should this occur, respond by immediately
reducing your speed. Proceed carefully to
the nearest BMW center or professional tire
center, or have the vehicle towed there to
have it and its wheels or tires inspected.
Tire damage up to and including sudden
and complete air loss can pose an extreme
hazard for both vehicle occupants and
other road users.<

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Wheel and tire replacement
Unprofessional attempts by laymen to
service tires can lead to damage and
accidents.
Have this work performed by skilled pro-
fessionals only. Any BMW center has the
required technical knowledge and the
proper equipment and will be happy to
assist you.<
The correct wheel and tire combination
also affects various systems that would
otherwise be impaired, for example ABS or
DSC.
Have the wheels balanced after each tire or
wheel replacement.
BMW advises against using retreaded
tires, since driving safety may be
impaired. This is due to possible variations
in casing structures and, in some cases, to
their extreme age, factors which can lead
to a decrease in their durability.<
The correct wheels and tires
BMW recommends using only wheels
and tires that have been tested and
approved by BMW for your particular vehi-
cle model, as otherwise body contact and
serious accidents can result despite the
use of the same nominal size, e.g. due to
manufacturing tolerances. If non-approved
wheels and tires are used, BMW cannot
evaluate their suitability, and therefore can-
not be held liable for driving safety.<
To maintain good handling and vehicle
response, use only tires of a single brand
and tread configuration. In the event of a
flat tire, remount the previous wheel and
tire combination as soon as possible.
Recommended tire sizes and brands
BMW tests certain tire brands for each tire
size, classifies them as road-safe and
approves them. You can best find out
about these at a specialized shop, particu-
larly your BMW center. Observe any coun-
try-specific regulations, e.g. on making a
corresponding entry in the vehicle docu-
ments.The factory-approved radial-ply tires are
matched to your vehicle and have been
selected to provide optimum safety and
driving comfort when used properly.
Run Flat tires fitted
Use only Run Flat tires, since no spare
wheel is available in the event of a flat.
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 designa-
tion, provide better winter traction than
summer tires, they generally do not achieve
the full performance of winter tires.
For mounting winter tires, refer to the
descriptions under Tire condition and
Wheel and tire replacement, pages 78, 79.
Run Flat tires fitted
Use only winter Run Flat tires, since no
spare wheel is available in the event of a
flat.
Observing speed ratings
Never exceed the maximum speed for
which the winter tires are rated.
Unprofessional attempts by laymen to ser-
vice tires can lead to damage and acci-
dents. Have this work performed by skilled
professionals only. The technicans at your
BMW center will be glad to assist you with
the required professional knowledge and
specialized equipment.<
Storage
Store tires in a cool, dry place, protecting
them against light whenever possible. Pro-
tect the tires from contact with oil, grease
and fuel. Do not exceed the maximum tire
inflation pressures specified on the tire
sidewall.

In the engine compartment
84 The oil volume between the two marks on
the dipstick corresponds to approx.
1.1 quarts/1 liter. Do not fill beyond the
upper mark on the dipstick. Excess oil will
damage the engine.
Adding engine oil
While you should wait until the level has
dropped to just above the lower mark
before adding oil, you should never allow
the oil level to fall below this mark.
BMW engines are designed to oper-
ate without oil additives; the use of
additives could even lead to damage in
some cases. This also applies to manual
and automatic transmissions and to the dif-
ferential.<
Continuous exposure to used oil has
caused cancer in laboratory tests. For
this reason, thoroughly wash any areas of
skin that come into contact with oil using
soap and water.
Always store oils, grease and similar mate-
rials so that they are inaccessible to chil-
dren. Comply with warning labels and the
information on the containers.<
Comply with the applicable environ-
mental laws regulating the disposal of
used oil.<
Approved engine oils
The quality of the engine oil is extremely
important for the function and life of an
engine. Based on extensive testing, BMW
has approved certain grades of engine oil.
Use approved High Performance Synthetic
Oil.
If you are unable to obtain an approved
High Performance Synthetic Oil, you may use small volumes of other synthetic oils for
topping up between oil changes. Use only
oils with the specification API SH or higher.
Ask your BMW center for details con-
cerning the specific High Perfor-
mance Synthetic Oil or synthetic oils that
have been approved.<
You can also call BMW of North America
toll-free at 1-800-831-1117 or visit this
website: www.bmwusa.com to obtain this
information.
Coolant
The yellow coolant indicator lamp
lights up:
The coolant level is too low: top up
as soon as possible.
Do not add coolant to the cooling sys-
tem when the engine is hot. If you do,
escaping coolant can cause burns.
Antifreeze and anti-corrosion agents are
hazardous to health. You should always
store them in their original containers and
in a location inaccessible to children.
Antifreeze and anti-corrosion agents are
flammable. For this reason, do not spill
them on hot engine parts. They could ignite
and cause burns. Comply with the instruc-
tions on the containers.<
Checking the coolant level
Correct coolant level when the engine is
cold, approx. 687/206:
1.Open the cap of the expansion tank by
turning it slightly counterclockwise to

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Laws and regulations
California Proposition 65
warning
California laws require us to state the fol-
lowing warning:
Engine exhaust and a wide variety of
automobile components and parts,
including components found in the interior
furnishings in a vehicle, contain or emit
chemicals known to the State of California
to cause cancer and birth defects and
reproductive harm. In addition, certain flu-
ids contained in vehicles and certain prod-
ucts of component wear contain or emit
chemicals known to the State of CA to
cause cancer and birth defects or other
reproductive harm. Battery posts, terminals
and related accessories contain lead and
lead compounds. Wash your hands after
handling. Used engine oil contains chemi-
cals that have caused cancer in laboratory
animals. Always protect your skin by wash-
ing thoroughly with soap and water.<
OBD interface socket
The Onboard Diagnostic OBD interface
socket is located on the left of the driver's
side under the instrument panel and under
a cover.
The cover has the letters OBD on it.
The purpose of the OBD system is to
ensure proper operation of the emission
control system for the vehicle's lifetime. The system monitors emission-related
components and system for deterioration
and malfunction.
If the Service Engine Soon indicator
lamp comes on either continuously
or intermittently, this indicates a
fault in the emissions-related electronic
systems. Although the vehicle remains
operational, you should have the systems
checked by your BMW center at the earli-
est possible opportunity.
The illuminated indicator informs you of the
need for service, not that you need to stop
the vehicle. However, the systems should
be checked by your BMW center at the
next opportunity.
If the indicator blinks or flashes, this indi-
cates a high level of engine misfire. Reduce
speed and contact the nearest BMW center
immediately. Severe engine misfiring over
even a short period of time can seriously
damage emission control system compo-
nents, especially the catalytic converter.
Service Engine Soon warning lamp
for Canadian models.
If the gas cap is not on tight enough,
the OBD system can detect leaking
vapor and the indicator will light up. If the
gas cap is then tightened, the indicator will
usually go out after a short period of time.<