BMW Z4 COUPE 3.0SI 2008 Manual Online

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Mobility
79

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

Refueling
82
Refueling
Always switch off the engine before refu-
eling. Otherwise the tank cannot be
refilled. The Service Engine Soon warning lamp
will come on.<
Take all precautionary measures and
observe all applicable regulations when
handling fuel. Do not carry any spare fuel con-
tainers in your vehicle. They can develop a leak
and cause an explosion or cause a fire in the
event of an accident.<
Gas cap
Opening
1.Open the fuel filler door, arrow 1.
2.Turn the gas cap counterclockwise.
3.Place the gas cap in the bracket attached to
the fuel filler door, arrow 2.
Closing
Fit the gas cap and turn it clockwise until you
clearly hear a click.
Do not jam the gas cap strap as this will
allow fuel vapors to escape.<
The warning lamp
* lights up briefly if
the gas cap is loose or missing. Close
the gas cap properly.
Manually releasing the fuel filler door
In the event of a malfunction you can unlock the
fuel filler door manually.1.Remove the cover for the right-hand rear
lamps in the cargo bay by turning the lock,
see arrow.
2.Pull the cargo bay trim panel slightly toward
the interior. The green button with the fuel
pump symbol becomes visible.
3.Undo the adhesive strip and pull off.
4.Pull the button. The fuel filler door is
released.
Pull on the button slowly and care-
fully; otherwise it could be torn off.<
Observe the following when refueling
When handling fuels, comply with all of
the applicable safety precautions posted
at the service station.<
When refueling, insert the filler nozzle com-
pletely into the filler pipe. Avoid lifting the filler
nozzle while filling the tank, as it could other-
wise lead to:
>Premature pump shutoff
>A reduced efficiency of the fuel-vapor
recovery system.

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The fuel tank is full when the filler nozzle shuts
off the first time.
Fuel tank capacity
Approx. 14.5 US gallons/55 liters, including the
reserve capacity of approx. 2.1 US gallons/
8liters.
Do not drive until the fuel tank is empty.
Otherwise, the engine may not operate
properly and damage could result.<
Fuel specifications
Do not fill the tank with leaded fuel, as this
would cause permanent damage to the
catalytic converter.
Do not fill the tank with E85, i.e. fuel that con-
tains 85 % ethanol, nor with Flex Fuel, as this
would cause damage to the engine and fuel
supply system.<
Required fuel
Super Premium Gasoline/AKI 91
This gasoline is highly recommended.
However, you may also use gasoline with less
AKI. The minimum AKI Rating is 87.
If you use gasoline with this minimum AKI Rat-
ing, the engine may produce knocking sounds
when starting at high outside temperatures.
This has no effect on the engine life.
Do not fill the tank with gasoline below the
specified minimum grade; otherwise
engine damage could result.<
Use high-quality brands
Field experience has indicated significant dif-
ferences in fuel quality: volatility, composition,
additives, etc., among gasolines offered for sale
in the United States and Canada. Fuels contain-
ing up to and including 10 % ethanol or other
oxygenates with up to 2.8 % oxygen by weight,
that is, 15 % MTBE or 3 % methanol plus an
equivalent amount of co-solvent, will not void
the applicable warranties with respect to
defects in materials or workmanship.The use of poor-quality fuels may result in
drivability, starting and stalling problems
especially under certain environmental condi-
tions such as high ambient temperature and
high altitude.
Should you encounter driveability problems
which you suspect could be related to the fuel
you are using, we recommend that you respond
by switching to a recognized high-quality brand
such as gasoline that is advertised as Top Tier
Detergent Gasoline.
Failure to comply with these recommendations
may also result in unscheduled maintenance.<

Wheels and tires
84
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.After the tire inflation pressure is cor-
rected, initialize the Flat Tire Monitor
*,
refer to page53, or reset the Tire Pressure
Monitor
*, refer to page54.<
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.

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Z4 Roadster 3.0i
Z4 Roadster 3.0si
Tire sizePressure specifications in psi/kPa
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 W
205/55 R 16 91 H M+S
225/50 R 16 92 H M+S
225/45 R 17 91 H/V M+S32/220 35/240
Front: 225/45 R 17 91W
Rear: 255/40 R 17 94 W32/220
––
35/240
Front: 225/40 R 18 88 W
Rear: 255/35 R 18 90 W32/220
––
35/240
You will find more information about permissible loads and weights on page113.
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 38/260
Front: 225/45 R 17 91W
Rear: 255/40 R 17 94 W33/230
––
38/260
Front: 225/40 R 18 88 W
Rear: 255/35 R 18 90 W33/230
––
38/260
You will find more information about permissible loads and weights on page113.

Wheels and tires
86
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 page113.
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 page88.
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
88 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.
To continue driving with a damaged tire:
>If the vehicle is equipped with the Flat Tire
Monitor, refer to Flat tire warning on
page53.
>If the vehicle is equipped with the Tire Pres-
sure Monitor, refer to Warning of low tire
inflation pressure on page54.
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.<