2004 BMW M3 COUPE Owner's Manual

113
Corrosion on brake rotors is signaled by
a running or pulsation during braking;
even extended subsequent braking will
not cure this phenomenon.
It is a good idea to periodically dry the
brakes with a gentle application when
driving in rain and on wet roads. Watch
traffic conditions to ensure that this
maneuver does not endanger other
road users. The heat generated in this
process helps dry the pads and rotors
to ensure that your brake system will
respond with undiminished efficiency
when you need it.
Extended or steep mountain descents
should be driven in the gear in which
only minimal periodic brake applica-
tions are required. This helps avoid
placing excessive loads on the brake
system. Stay within the allowable rpm
range. For additional information, refer
to page 76.
Do not coast with the clutch
depressed or with the gearshift
lever in idle. Do not coast with the
engine switched off. If you do so the
engine provides no braking effect and
there is no power assist for braking or
steering when the engine is not run-
ning.<
Brake pads
For your own safety: use only
brake pads which BMW has
approved for your specific vehicle
model. BMW cannot evaluate non-
approved brake pads to determine if
they are suitable for use, and therefore
cannot ensure the operating safety of
the vehicle if they are installed.<
Brake system
OverviewControlsMaintenanceRepairsDataIndex

114Wheels and tires
Tire inflation pressureInformation for your safetyThe factory-approved tires are matched
to your vehicle and have been selected
to provide optimum safety and driving
comfort when used properly.
It is not merely the tire's service life, but
also driving comfort and – above all else
– driving safety that depend on the con-
dition of the tires and the maintenance
of the specified tire pressure.
Incorrect tire inflation pressure is
a frequent cause of tire damage. It
also significantly influences the road-
holding ability of your BMW. Check tire
inflation pressures on a regular basis,
refer to page 25, at least every two
weeks and before beginning a longer
trip. If this is not done, incorrect tire
pressures can cause driving instability
and tire damage, ultimately resulting in
accidents.<
Tire conditionTire tread – tire damageInspect 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
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 great risk of hydroplaning, even at
relatively moderate speeds and with
only small amounts of water on the
road. Tread wear indicators in the
tread-groove base – see arrow – are
distributed around the wheel circumfer-
ence and are labeled on the tire side-
wall with TWI – Tread Wear Indicator. At
a tread depth of 1/16 in / 1.6 mm, the
indicators signal that the legally permis-
sible wear limit has been reached.

115
Do not drive on a deflated – flat –
tire. A flat tire greatly impairs
steering and braking response, and can
lead to complete loss of control over
the vehicle.
Avoid overloading the vehicle so that
the permitted load on the tires is not
exceeded. Overloading can lead to
overheating and internal tire damage.
This can result in a sudden loss of tire
inflation pressure.
Unusual vibrations encountered during
normal vehicle operation can indicate
tire failure or some other vehicle defect.
This type of problem can be caused by
contact with curbs, etc. This is also true
for irregularities in the vehicle's han-
dling characteristics, such as a pro-
nounced tendency to pull to the left or
right. Should this occur, respond by
immediately reducing your speed. Pro-
ceed carefully to the nearest BMW cen-
ter or professional tire center, or have
the vehicle towed in to have it, its
wheels or its tires inspected.
Tire damage, up to and including blow-
outs, can endanger the lives of both the
vehicle occupants and other road
users.<
Tire replacementTo maintain good handling and vehicle
response, use only tires of a single
tread configuration from a single manu-
facturer.
Comply with the specified tire inflation
pressures – and be sure to have the
wheel and tire assembly balanced
every time you change a tire or wheel.DOT quality gradesTreadwear
Traction AA A B C
Temperature A B C
All passenger car tires must con-
form to Federal Safety Require-
ments in addition to these grades. rating based on the wear rate of the tire
when tested under controlled condi-
tions on a specified government test
course.
For example, a tire graded 150 would
wear one and one-half – 1
1/2 – times as
well on the government course as a tire
graded 100. The relative performance
of tires depends upon the actual condi-
tions of their use, however, and may
depart significantly from the norm due
to variations in driving habits, service
practices and differences in road char-
acteristics and climate.TractionThe 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 speci-
fied government 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 braking traction tests, and does
not include acceleration, cornering,
hydroplaning, or peak traction charac-
teristics. highest – B and C, representing the
tire's resistance to the generation of
heat and its ability to dissipate heat
when tested under controlled condi-
tions on a specified indoor laboratory
test wheel.
Tire condition
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116
Sustained high temperature can cause
the material of the tire to degenerate
and reduce tire life, and excessive tem-
perature 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 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, under-inflation, or
excessive loading, either separately or
in combination, can cause heat buildup
and possible tire failure. applicable on the tire sidewall between
tread shoulder and maximum section
width. For example:
Treadwear 200 Traction AA
Temperature A
Tire ageBMW recommends the replacement of
all tires when the tires are no more than
6 years old, even if a tire life of 10 years
is possible.
The date on which the tire was manu-
factured is indicated by the code on the
sidewall:
DOT ... 3603 indicates that the tire was
manufactured in week 36 of the year
2003.Following wheel/tire changesComply with the specified tire inflation
pressures – and be sure to have the
wheel and tire assembly balanced
every time you change a tire or wheel.
Following wheel and/or tire changes
you will need to reinitialize both the Flat
Tire Monitor and the sequential M gear-
box with Drivelogic, refer to pages 71,
85.
Tire replacement

117
Wheel and tire combinationsThe right choice
BMW recommends using only
wheels and tires that have been
approved by BMW for your particular
vehicle model, as otherwise body con-
tact and serious accidents can result
despite the use of the same nominal
size, e.g. due to manufacturing toler-
ances. 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 corresponding entry in the
vehicle documents.
The correct wheel and tire combi-
nation affects different systems
such as ABS, DSC, Flat Tire Monitor.
The function of these systems is
impaired if improper wheel and tire
combinations are used.
Therefore, only use tires of the same
brand and same tread configuration on
the vehicle and, for example following a
tire failure, restore the approved wheel
and tire combination as soon as possi-
ble.<
The use of rims and lug bolts that
do not meet the specifications of
the original factory-installed equipment
will affect the safe operation of your
vehicle and may cause an accident and
personal injury.
Never mix tires of different design, such
as steel-belted radials with radial bias-
belted or bias-ply tires, etc. Mixing tire
types will adversely affect roadholding
and can lead to loss of vehicle con-
trol.<
StorageAlways store tires in a cool, dry place.
Store them away from light whenever
possible. Protect the tires against con-
tact with oil, grease and fuel.
Do not exceed the maximum tire infla-
tion pressures specified on the tire
sidewall.
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118
Winter tiresChoosing the right tireBMW 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 the corresponding sum-
mer tires, they generally do not achieve
the performance of winter tires.
In the interest of safe tracking and
steering response, install radial tires
made by the same manufacturer and
with the same tread configuration on all
four wheels if you elect to mount winter
tires.
When mounting winter wheels,
observe the different recesses of
the front and rear wheels, as otherwise
damage may result.<
Do not exceed specified
maximum speeds
Never exceed the maximum
speed for which the winter tires
are rated.
Unprofessional attempts by laymen to
service tires can lead to damage and
accidents.
Have this work performed by skilled
professionals only. Your BMW center
will be glad to assist you with both their
expertise and the proper equipment for
your vehicle.<
Tire condition, tire pressureAt tread depths below approx. 3/16 in /
4 mm, tire performance under winter
driving conditions deteriorates notice-
ably. Worn tires should therefore be
replaced for safety considerations.
Comply with the specified tire inflation
pressures – and be sure to have the
wheel and tire assembly balanced
every time you change a tire or wheel.
Snow chains*Only certain snow chains have been
tested by BMW and determined and
approved as roadworthy. Consult your
BMW center for more information.
BMW recommends using only these
approved fine-link snow chains. Use
them in pairs on winter tires, but only on
both rear wheels.
Comply with all manufacturer's safety
precautions when mounting the chains.
Do not exceed a maximum speed of
30 mph / 50 km/h when using snow
chains.
After mounting or removing snow
chains, always reinitialize the sequential
M gearbox with Drivelogic, refer to
page 71.
It is not possible to mount snow
chains on tires with 18-inch and
19-inch wheels.
Deactivate the Flat Tire Monitor when
using snow chains. Malfunction warn-
ings and undetected losses in pressure
are a possibility when driving with snow
chains.
For additional information, refer to
page 84.<

119 In the engine compartment
HoodTo releasePull the lever located under the left-
hand side of the instrument panel.
Do not attempt to service your
vehicle if you do not have the
required technical background. Failure
to work in an informed, professional
manner when servicing components
and materials constitutes a safety haz-
ard for vehicle occupants and other
road users. If you are not familiar with
the guidelines, BMW recommends that
you have the operations performed by
your BMW center.<
To openPull the release handle and open the
hood.
It is not possible to drive off using
SMG Drivelogic when the hood is
open.<
To closePull the hood downwards and allow it to
fall from a minimum height of 1 ft/30 cm
so that it audibly engages. Check for
proper locking by pulling on the hood at
the left and right above the headlamps.
To avoid injuries, be sure that the
travel path of the hood is clear
when it is closed, following the same
safety precautions used in all closing
procedures.
If you notice while driving that the hood
is not completely closed, stop immedi-
ately and close it securely.<
OverviewControlsMaintenanceRepairsDataIndex

120
Engine compartment essentials