ESP BMW 320i 2003 Owner's Guide

117 Wheels 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 pressure
of 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.
Otherwise, incorrect tire pressure can
lead to poor handling, to tire damage
and 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.
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 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 irregularities 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-
OverviewControlsMaintenanceRepairsDataIndex

118
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.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.
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
Tire condition

120
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-tire combina-
tion affects various systems such
as ABS, ASC+T/DSC and ADB/
ADB-X/DBC. The function of these sys-
tems is impaired if improper wheel-tire
combinations are used.
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.<
StorageStore tires in a cool, dry place, protect-
ing them against light whenever possi-
ble. Protect the tires against contact
with oil, grease and fuel.
Winter tiresChoosing the right tireBMW recommends winter tires – M+S
tires – for operation under inclement
winter driving conditions. While all-sea-
son tires – M+S designation – provide
better winter traction than the corre-
sponding summer tires, they generally
do not achieve the performance of win-
ter 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.<

126
Washer fluidsHeadlamp* and windshield
washer systemCapacity approx.
5.6 US quarts/5.3 liters
Fill with water and – if required – with a
washer antifreeze additive according to
manufacturer's recommendations.
We recommend that you mix the
washer fluid before adding it to
the reservoir.<
Antifreeze agents for the washer
fluid are highly flammable. For this
reason, keep them away from sources
of flame and store only in original con-
tainers. Store them inaccessible to chil-
dren. Comply with the instructions on
the containers.<
Engine oilChecking the oil level1. Park the vehicle on a level surface
2. Switch the engine off after it has
reached normal operating tempera-
ture
3. After approx. 5 minutes, pull the dip-
stick out and wipe it off with a clean
lint-free cloth, paper towel, or similar
material
4. Carefully push the dipstick all the
way into the guide tube and pull it
out again
5. The oil level should be between the
two marks on the dipstick.
As with fuel economy, oil consumption
is directly influenced by your driving
style and vehicle operating conditions.
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.

132
engine misfiring for even a short period
of time can seriously damage emission
control system components, especially
the catalytic converter.
SERVICE ENGINE SOON warn-
ing 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.

146
BatteryMaintenanceThe battery is maintenance-free, that is,
the original electrolyte will normally last
for the service life of the battery under
moderate climatic conditions.
Please consult your BMW center
whenever you have any questions
concerning the battery. The battery is
completely maintenance-free; the fol-
lowing section is provided for your
information only.<
Never disconnect the battery
when the engine is running; the
ensuing voltage surge would seriously
damage the vehicle's onboard elec-
tronic systems. cle, leave the engine off at all times.
Connect the charge cables to the termi-
nals in the engine compartment. For
terminal locations, refer to Jump-start-
ing on page 147.
Return used batteries to a recy-
cling point or your BMW center.
Maintain the battery in an upright posi-
tion for transport and storage. Secure
the battery against tilting during trans-
port.<
FusesYou will find the fuses and information
on their respective allocation in the
glove compartment behind a panel with
two snap clips.
Do not attempt to repair a blown
fuse or replace it with a fuse
having a different color or amperage
rating. To do this could cause a fire in
the vehicle resulting from a circuit over-
load.<

Refueling
To ensure that you always have conve-
nient access to all essential information
when you stop for fuel, we recommend
that you fill out the adjoining chart by
entering the data that apply to your
vehicle. Consult the index for individual
specifications.
FuelPlease enter your preferred fuel here.Engine oilThe oil volume between the two marks
on the dipstick corresponds to approx.
1.1 US quarts/1 liter.Tire inflation pressureDesignation
Quality
Summer tires Winter tires
Front Rear Front Rear
Up to 4 persons
5 persons or 4 plus luggage