2004 BMW 320i maintenance

115
Determining the maximum load1. Locate the following statement on
your vehicle's placard*:
The combined weight of occu-
pants and cargo should never
exceed XXX kg or YYY lbs., as this
could otherwise result in damage to the
vehicle or unstable driving conditions.<
2. Determine the combined weight of
the driver and passengers that will be
riding in your vehicle
3. Subtract the combined weight of the
driver and passengers from
XXX kilograms or YYY pounds
4. The resulting figure equals the avail-
able amount of cargo and luggage
load capacity.
For example, if the XXX amount
equals 1,400 lbs. and there will be
five 150 lbs. passengers in your vehi-
cle, the amount of available cargo
and luggage load capacity is
650 lbs.:
1,400 lbs. minus 750 lbs. = 650 lbs.
5. Determine the combined weight of
luggage and cargo being loaded on
the vehicle. That weight may not
safely exceed the available cargo
and luggage load capacity calculated
in Step 4
6. If your vehicle will be towing a trailer,
load from your trailer will be trans-
fered to your vehicle. Consult the
manual for transporting a trailer to
determine how this may reduce the
available cargo and luggage load
capacity of your vehicle.
Stowing cargo>Load heavy cargo as far forward as
possible – directly behind the back-
rests or the luggage compartment
partition – and as low as possible
>Cover sharp edges and corners
>Do not pile objects higher than the
top edge of the backrest
Cargo loading
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117
Roof-mounted luggage rack*A special roof-rack system is available
as an optional extra for your BMW.
Please observe the precautions
included with the installation instruc-
tions.AnchoragesAccess to the anchorages:
To fold up the covers, please use the
tool provided with the roof-rack system.Loading and driving notesRoof-mounted luggage racks raise the
center of gravity of the vehicle when
they are loaded. For this reason, they
exercise a major effect on the vehicle's
handling and steering response.
You should therefore always remember
not to exceed the approved roof load
capacity, the approved gross vehicle
weight or the axle loads when loading
the rack. These weights are listed under
Technical data on page 162.
Make sure that the load is not too
heavy, and attempt to distribute it
evenly. Always load the heaviest pieces
first so that they are at the bottom. Be
sure that adequate clearance is main-
tained for raising the glass sunroof, and
that objects do not project into the
opening path of the luggage compart-
ment lid.
Secure the roof-mounted luggage cor-
rectly and securely to prevent it from
shifting or being lost during driving.
Drive smoothly and avoid sudden
acceleration and braking. Do not corner
at high speeds.
The roof-mounted luggage rack and the
roof load increase the aerodynamic
resistance: increased fuel consumption
and additional stress on the vehicle's
body are the result.
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119
Overview
Controls and features
Operation, maintenance
Owner service procedures
Technical data
Index
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121
General driving notes
Brakes: do not rest your foot on
the brake pedal while driving.
Even light but consistent pedal pres-
sure can lead to high temperatures,
brake wear and possibly even brake
failure.
Hydroplaning: when driving on wet or
slushy roads, reduce road speed. If you
do not, a wedge of water can form
between tires and road surface. This
phenomenon can lead to partial or
complete loss of contact between the
tires and road surface, as well as loss of
vehicle control and braking ability.
Driving through water: do not drive
through water on the road if it is deeper
than 1 ft/30 cm, and then only at walk-
ing speed. Otherwise, the vehicle's
engine, the electrical systems and the
transmission may be damaged.
Rear parcel tray: never use it to store
heavy or hard objects; otherwise, occu-
pants could be injured if the vehicle is
braked hard.
Clothes hooks: when hanging clothing
from the hooks, be sure that they will
not obstruct the driver's vision. Do not
hang heavy objects on the hooks. If you
do so, they could cause personal injury
during braking or evasive maneuvers.<
Antilock Brake System (ABS)The conceptABS keeps the wheels from locking
during braking, thereby enhancing
active driving safety.Braking with ABSIf you are in a situation that requires full
braking, you will exploit the full benefits
of the ABS system if you apply maxi-
mum pedal pressure – panic stop.
Since the vehicle maintains steering
responsiveness, you can avoid possible
obstacles with a minimum of steering
effort, despite the full brake application.
Pulsation at the brake pedal combined
with sounds from the hydraulic circuits
indicates to the driver that ABS is in its
active mode.Dynamic Brake Control (DBC)DBC is included in the DSC, refer to
page 87.
The system responds to sudden, high-
intensity applications of force to the
brake pedal by automatically braking
the vehicle with maximum boost to
achieve the shortest possible braking
distances during panic stops. This sys-
tem exploits all the benefits of ABS.Do not reduce the pressure exerted
against the brake pedal until the brak-
ing maneuver has been completed.
DBC is deactivated when you release
the brake pedal.
Cornering Brake Control (CBC)CBC is an advanced engineering
design of the ABS. When braking while
cornering at high speed or braking dur-
ing high lateral acceleration, or when
braking during a lane change, vehicle
stability is improved and steering
response is enhanced.
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123
Portable phone in the vehicleBMW recommends using mobile com-
munications devices, e.g. portable
phones, inside the vehicle with a suit-
able outside antenna. Otherwise, it can-
not be ruled out that the vehicle elec-
tronics and portable phone may
interfere with each other.Brake system
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124Wheels 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 inflation pressure.
Incorrect tire inflation pressure is a fre-
quent cause of tire damage. Tire pres-
sure also has a major effect on your
BMW's handling response.
Be sure to check the tire inflation
pressure, including the space-
saver spare tire or the spare tire, on a
regular basis, at least twice a month
and before every extended journey,
refer to page 25. If this is not done,
incorrect tire pressures can cause driv-
ing instability and tire damage, ulti-
mately 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 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.

125
Do not drive on a 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. Avoid overloading the vehi-
cle so that the permitted load on the
tires is not exceeded. Overloading can
lead to overheating and internal tire
damage.
The ultimate result can assume the
form of a sudden air loss.
Unusual vibrations encountered during
normal vehicle operation can indicate a
flat tire or some other vehicle malfunc-
tion. This type of problem can be
caused by contact with curbs, etc. This
is also true for abnormalities in the vehi-
cle's handling characteristics, such as a
pronounced 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 sud-
den and complete air loss can endan-
ger the lives of both the vehicle occu-
pants 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 gradesTread wear
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.
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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127
Wheel and tire combinationsThe right choice
BMW recommends using only
wheels and tires that have been
approved by BMW for use on your par-
ticular model. Although other wheels
and tires may theoretically have the
same dimensions, variations in factors
such as manufacturing tolerances can
result in contact between tire and body-
work, ultimately leading to serious acci-
dents. BMW cannot evaluate all tires
and wheels on the market, and is thus
unable to guarantee that the vehicle will
continue to perform safely if unap-
proved tires and/or wheels are
mounted.<
For each tire size, BMW has assessed
the safe performance of specific tire
brands and approved them for use.
Consult any BMW center for details.
Comply with any local/national regula-
tions, for example by recording the tire
type in the vehicle documents.
The correct wheel and tire combi-
nation affects various systems
that would otherwise be impaired, for
example ABS, DSC and ADB-X/DBC.
For this reason, use only tires of the
same manufacture and tread configura-
tion. In the event of a flat tire, for exam-
ple, remount the approved wheel and
tire combination as soon as possible.<
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.
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 winter tires
made by the same manufacturer and
having the same tread configuration on
all four wheels.
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 trained
professionals only. Any BMW center
has the required technical knowledge
and the proper equipment and will be
happy to assist you. your BMW is eqipped with Run Flat
tires. These are indicated by a circular
symbol containing the letters RSC on
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