2003 BMW 3.0i ROADSTER ESP

Wheels and tires
72
Z4 roadster 2.5i
Z4 roadster 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
225/45 R 17 30/210 33/230
225/40 R 18 30/210 –
245/40 R 17
255/35 R 18 –33/230
All winter tires 30/210 33/230
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 33/230 36/250
225/40 R 18 33/230 –
245/40 R 17
255/35 R 18 –36/250
All winter tires 33/230 36/250

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Reference
73
Tire condition
Tire tread – Tire damage
Inspect your tires frequently for tread wear,
signs of damage and for foreign objects
lodged in the tread. Check the tread depth.
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.
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
Indicator. At a tread depth of
1/16 in /
1.6 mm, the indicators signal that the
legally permissible wear limit has been
reached.
Avoid overloading the vehicle so that
the permitted load on the tires is not
exceeded. Overloading can cause over-
heating and damage inside the tires.
The ultimate result can assume the form of
a sudden air loss.
Unusual vibrations encountered during
normal vehicle operation can indicate tire
failure or some other vehicle malfunction.
This type of problem can be caused by
contact with curbs, etc. This is also true for
irregularities in the vehicle's handling char-
acteristics, such as a pronounced ten-
dency to pull to the left or right. Should this
occur, respond by immediately reducing
your speed. Proceed carefully to the near-
est 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.<
Tire replacement
To maintain good handling and vehicle
response, use tires of a single tread config-
uration from a single manufacturer.
BMW advises against using retreaded
tires as this could negatively affect
driving safety. This is due to possible varia-
tions in casing structures and, in some
cases, to their extreme age, factors which
can lead to a decrease in their durability.<
Tire age
The date on which the tire was manufac-
tured is indicated by the code on the side-
wall:
DOT … 3602 indicates that the tire was
manufactured in week 36 of the year 2002.
BMW recommends the replacement of all
tires every 6 years at the latest, even if a tire
usage of 10 years is possible.
Run Flat tires
When replacing tires, always use
Run Flat tires since a spare wheel is
not provided to replace a flat tire.
Run Flat tires are labeled on the sidewall
with a circular symbol containing the letters
RSC. Refer to page 75.<
DOT quality grades
Tread wear
Traction AA A B C
Temperature A B C
All passenger car tires must conform
to Federal Safety Requirements in
addition to these grades.<
Tread wear
The tread wear grade is a comparative rat-
ing based on the wear rate of the tire when
tested under controlled conditions on a
specified government test course.
For example, a tire graded 150 would wear

Wheels and tires
74 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,
however, and may depart significantly from
the norm due to variations in driving habits,
service practices and differences 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 govern-
ment test surfaces 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 brak-
ing traction tests, and does not include
acceleration, cornering, hydroplaning, or
peak traction characteristics.<
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 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.<
Uniform Tire Quality Grading
Quality grades can be found where appli-
cable on the tire sidewall between tread
shoulder and maximum section width. For
example:
Tread wear 200 Traction AA
Temperature A
Wheel and tire combina-
tions
The right choice
Use wheels and tires approved by
BMW for your particular vehicle. Vari-
ations in factors such as manufacturing tol-
erances mean that even wheels and tires
with identical official size ratings could
actually have dimensions different from the
approved units. These differences could
lead to body contact, and with it the risk of
severe accidents. If non-approved wheels
and tires are used, BMW cannot evaluate
their suitability, and therefore cannot be
held liable for driving safety.<
BMW tests certain tire brands for each tire
size, classifies them as road-safe and
approves them. Consult your BMW center
for more information. Observe any country-
specific regulations, e.g. on making a cor-
responding entry in the vehicle documents.
The correct wheel and tire combina-
tion affects different systems such as
ABS, DSC, DTC and DBC. The function of
these systems is impaired if improper
wheel and tire combinations are used.
For this reason, use tires of the same brand
and tread configuration. In the event of a
flat tire, for example, remount the approved
wheel and tire combination as soon as pos-
sible.<

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Run Flat tires
Run Flat tires are labeled on the sidewall
with a circular symbol containing the letters
RSC.
Run Flat tires consist of self-supporting
tires and special rims. The tire reinforce-
ment ensures that the tire retains some
residual safety in the event of pressure
drop and driving remains possible to a
restricted degree.
Because the sides of the Run Flat
tires are reinforced, a drop in inflation
pressure usually cannot be detected from
the outside.<
Flat tire
The red warning lamp in the instru-
ment cluster lights up when a tire
has failed. In addition, an acoustic
signal is heard. Refer to pages 14, 53.
1.Reduce vehicle speed carefully to
under 50 mph / 80 km/h. Avoid hard
brake applications and steering maneu-
vers
2.Do not exceed 50 mph / 80 km/h again
3.Find out which tire has been damaged;
to do so, check the tire inflation pres-
sure of all four tires at the earliest
opportunity. Refer to page 71
4.Correct the tire inflation pressure if you
wish to continue driving and if it is safe
to do so. Refer to the following section
5.Have the damaged tires changed by
your BMW center.
BMW recommends that you consult
your BMW center if you wish to replace the tires of your BMW, or change
from summer to winter tires or vice versa.
Your BMW center knows how to work with
Run Flat tires and is equipped with the nec-
essary special tools.<
For safety reasons, do not have Run
Flat tires repaired.
When replacing tires or changing from
summer to winter tires – or vice versa – use
Run Flat tires only since a spare tire will not
be available in the event of a flat tire.<
Driving with a damaged tire
When using Run Flat tires, you can con-
tinue driving cautiously at a maximum
speed of 50 mph / 80 km/h, depending on
the cargo load and the extent of tire dam-
age.
You can estimate the distance you can
continue driving on the basis of the follow-
ing values:
>Tire inflation pressure of 0 psi / 0 kPa:
approx. 100 miles / 150 km
>Tire inflation pressure of 7 – 15 psi
50 – 100 kPa:
approx. 300 miles / 500 km
>Tire inflation pressure greater than
15 psi / 100 kPa:
approx. 600 miles / 1,000 km.
Drive cautiously and do not exceed a
speed of 50 mph / 80 km/h. In the
event of pressure loss, changes in handling
characteristics – such as reduced stability
when braking, increased stopping dis-
tance, and altered steering response – may
occur.<

Wheels and tires
76
Winter tires
Choosing the right tire
BMW recommends Run Flat winter tires –
M+S – for operation under inclement winter
driving conditions. While all-season tires
with the M+S identification mark do indeed
possess better winter traction than summer
tires that have the H, V, W, Y and ZR speed
ratings, they generally do not provide the
same levels of performance as true winter
tires.
In the interests of sure tracking and safe
steering response, mount winter tires
which are made by the same manufacturer
and which have the same tread configura-
tion on all four wheels.
Your BMW is equipped with Run Flat tires.
Please consult your BMW center if you
wish to replace the tires of your BMW or
change from summer to winter tires, or vice
versa.
When replacing tires or changing from
summer to winter tires – or vice versa –
use only Run Flat tires since a spare tire will
not be available in the event of a flat tire.<
Comply with recommended speed
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 pro-
fessionals only. Any BMW center has the
required technical knowledge and the
proper equipment and will be happy to
assist you.<
Tire condition, tire pressure
Once the tire wears to below 3/16 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.
Comply with the specified tire inflation
pressures – and be sure to have the wheel
and tire assemblies balanced every time
you change the tires.
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.
Snow chains*
Only certain types of snow chains have
been tested by BMW, classified as road-
safe and approved. Consult your BMW
center for more information. BMW recom-
mends using only approved fine-link snow
chains.
Their use is only permitted in pairs on the
winter tires on the rear wheels. Comply
with all manufacturer's safety precautions
when mounting the chains.
You cannot mount snow chains on the fol-
lowing tires:
245/40 R 17
255/35 R 18
Do not exceed a speed of 30 mph /
50 km/h when using snow chains.<
Do not initialize the Flat Tire Monitor
after snow chains have been
mounted.
When driving with snow chains, it may be
useful to deactivate the DSC briefly. Refer
to page 51.<

In the engine compartment
80 The oil volume between the two marks on
the dipstick corresponds to approx.
1.1 US 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 "BMW High Performance
Synthetic Oil".
If you are unable to obtain an approved
BMW 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 BMW High Per-
formance 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 – at 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, some of its constitu-
ents, and certain vehicle components
contain or emit chemicals known to the
State of California to cause cancer and
birth defects and reproductive harm. In
addition, certain fluids contained in vehi-
cles and certain products of component
wear contain or emit chemicals known to
the State of California to cause cancer and
birth defects or other reproductive harm.
Battery posts, terminals and related acces-
sories contain lead and lead compounds.
Wash your hands after handling. Used
engine oil contains chemicals that have
caused cancer in laboratory animals.
Always protect your skin by washing thor-
oughly with soap and water.<
OBD interface socket
The Onboard Diagnostic OBD interface
socket is located on the left of the driver's
side behind a specially marked cover
located beneath the instrument panel. The
cover has the letters OBD on it.
This interface makes it possible to access
data on emissions – related components
using special equipment.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 fuel filler cap is not on tight
enough, the OBD system can detect
leaking vapor and the indicator will light up.
If the fuel filler cap is then tightened, the
indicator will usually go out after a short
period of time.<

Replacement procedures
88 Please consult your BMW center
whenever you have any questions
concerning the battery. Since the battery is
absolutely maintenance-free, the following
statements are for your information only.<
Do not disconnect the battery cables
when the engine is running. Discon-
necting the battery cables when the engine
is running will cause a voltage surge which
will damage the vehicle's onboard elec-
tronics.<
Indicator lamp
The indicator lamp for the battery
charge current lights up:
The battery is no longer being
charged. The alternator drive belt is defec-
tive or there is a malfunction in the charging
circuit of the alternator. Please contact the
nearest BMW center.
If the drive belt is defective, pull over
and switch off the engine immediately
to prevent overheating and serious engine
damage.
If the onboard supply voltage drops to a
very low level, increased steering effort
may also be necessary.<
Charging the battery
Charge the battery in the vehicle only when
the engine is not running. Use the terminals
provided in the engine compartment. For
information on connections, refer to Jump-
Starting on page 89.
Battery disposal
Return used batteries to a recycling
point or to your BMW center. Maintain
the battery in an upright position for trans-
port and storage. Secure the battery
against tilting when transporting.<
Fuses
You will find the fuses and information on
their respective allocation behind the glove
compartment.
1.Press the lock on the left; see arrow 1
2.Press the lock on the right; see arrow 2
3.Swing the glove compartment down.
Spare fuses and plastic tweezers for grasp-
ing the fuses are found in the onboard tool
kit; refer to page 84.
Do not attempt to repair a burned fuse
or replace it with a fuse having a dif-
ferent color or amperage rating. To do this
could cause a fire in the vehicle as a result
of circuit overload.<