2001 BMW 330XI SEDAN wheel

118n
Catalytic converter Antilock Brake System (ABS)
Be sure to comply with the
instructions above to prevent
unburned fuel from reaching the cata-
lytic convertor. If you do not, the cata-
lytic converter could respond by
overheating, leading to serious
damage.
Extreme temperatures occur at the
catalytic converter on this and every
catalyst-equipped vehicle. Heat shields
are installed adjacent to some sections
of the exhaust system. Never remove
these shields; do not apply under-
coating to their surfaces. When driving,
standing at idle, and parking the
vehicle, take extra care to avoid contact
between the exhaust system and flam-
mable materials (grass, hay, leaves,
etc.). Such contact could lead to a fire,
resulting in serious personal injury and
property damage.<
The concept ABS enhances active safety by helping
to prevent the wheels from locking
under braking. This is because locked
wheels are dangerous. When the front
wheels slide, the driver loses steering
control over the vehicle. Traction loss at
the rear wheels can cause the rear end
to break into an uncontrolled skid.
The system can achieve the shortest
braking distances possible under most
conditions (on straight-aways and in
curves, on asphalt, ice, wet road
surfaces, etc.).
ABS is designed to meet two essential
requirements during every brake appli-
cation:
>To help provide vehicle stability
>To help maintain steering control and
maneuverability Ð on all types of road
surfaces (asphalt, concrete, mud, wet
road surfaces, snow, ice).Braking with ABSThe system becomes operative once
the vehicle exceeds a speed of approx.
6 mph (10 km/h). Below approx. 4 mph
(6 km/h), it is once again deactivated.
This means that the wheels can lock in
the final phase of a panic stop Ð a factor
of no significance in actual use.If you are in a situation that requires full
braking, you will exploit the full benefits
of the ABS system if you apply
maximum brake 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.
The ABS system closed-loop control
circuit cycles in fractions of a second. A
pulsation at the brake pedal, together
with the sounds associated with the
hydraulic controls, tells you that the
brake system is within its maximum
limit range and reminds you that you
should adapt road speed to the road
conditions.
On road surfaces that have a loose
surface layer on a firm base with good
traction (on gravel or snow, for
example), or when snow chains are
mounted, braking distances may be
longer than with locked wheels.
However, ABS continues to provide
enhanced vehicle stability and steering
response under these conditions.
Information for your safetyNot even ABS can suspend the laws of
physics. ABS cannot prevent the

120n
Disc brakesDisc brakes furnish optimum decelera-
tion and braking control and greater
fade resistance under heavy use.
When the vehicle is driven only occa-
sionally, during extended periods when
the vehicle is not used at all, and in oper-
ating conditions where brake applica-
tions are less frequent, there is an
increased tendency for corrosion of the
discs and accumulation of contamina-
tion on the brake pads. This occurs
because the minimal pressure that must
be exerted by the pads to clean the
discs by brake applications is not
reached.
If the brake discs are corroded, they will
tend to respond to braking with a
pulsating effect that even extended
brake applications will fail to cure.
For your own safety: use only
brake pads that BMW has
approved for your particular vehicle
model. BMW cannot evaluate non-
approved brake pads to determine if
they are suited for use, and therefore
cannot ensure the operating safety of
the vehicle if they are installed.<
Driving notesWhen driving in wet conditions and in
heavy rain, it is effective to apply light
pressure to the brakes every few miles
or kilometers. Be aware of traffic condi-
tions to ensure that this maneuver does
not endanger other road users. The
heat that is generated by the brake
applications helps to dry the brake
pads and discs.
Maximum braking force is obtained
while the wheels are not locked, but
rather when they are still barely turning
immediately prior to locking. ABS main-
tains this state automatically. If the ABS
fails, you should revert to the staggered
braking technique described on
page 122.
Extended or steep mountain descents
should be driven in the gear in which
only minimal periodic brake application
is required. This avoids excessive strain
on the brakes and possible
impairment of the braking effect.
The braking effect of the engine can be
further increased by downshifting, into
first gear, if necessary. In the manual
mode of the automatic transmission,
you can also downshift into first gear.
Refer to page 66.Should engine braking prove inade-
quate, you should still avoid extended,
continuous braking. Instead of main-
taining low to moderate pressure over
an extended period of time, you should
decelerate by applying more substantial
pressure to the brake pedal (watch for
following traffic), releasing the pedal,
and then repeating the application
(staggered braking). The cooling
phases between active braking inter-
vals prevent the brakes from over-
heating, thus ensuring that full braking
capacity remains available at all times.
Do not coast with the clutch
depressed or with the shift lever
or selector lever in neutral. Do not drive
with the engine shut off. The engine
provides no braking effect when the
clutch is depressed or the transmission
is in neutral, and there is no power-
assist for braking or steering when the
engine is not running.
BMW 325xi, 330xi: have brake inspec-
tions performed at a BMW center only.
If you do not, parts of the four-wheel
drive system could be damaged.
Do not allow floor mats, carpets or any
other objects to protrude into the area
around the brake pedal, the clutch or
the accelerator which could obstruct
their freedom of movement.<

122n
Winter operationThe onset of winter is often accompa-
nied by rapid changes in weather.
Adaptations in driving style should be
accompanied by preparations on the
vehicle itself to ensure that your
progress through the winter remains
safe and trouble-free.CoolantBe sure that the coolant mixture
contains the year-round ratio of 50:50
water and extended-duty antifreeze/
corrosion protection. This mixture
provides protection against freezing
down to approx. -34 7 (-37 6).
Replace the coolant every four years.LocksBMW door lock deicer can be used to
free them if frozen. This deicer also
contains lubricant.
After its use, treatment with BMW lock
barrel grease is recommended.Rubber seals and components To prevent the weather-stripping from
freezing, apply a spray-on rubber treat-
ment or silicone spray to the door, hood
and luggage compartment lid seals.A full range of car care products is
available from your BMW center.<
Snow chains BMW snow chains can be mounted on
both summer and winter tires. Mount
them in pairs on the rear wheels only
and comply with the manufacturer's
safety precautions. Do not exceed a
maximum speed of 30 mph (50 km/h).
In this situation, it may be appropriate
to deactivate the ASC+T/DSC for a
short period of time. Refer to page 80.
BMW 325xi, 330xi: in a worst-case
scenario, if your vehicle is stuck on one
side or you cannot access one tire, then
a chain may be attached to one rear
wheel for a short period of time.Starting offWhen starting from a full stop in deep
snow or for "rocking" the vehicle to free
it, it may be effective to deactivate the
ASC+T/DSC system. Refer to page 80.Driving on low-traction road
surfacesUse smooth, gentle pressure to control
the accelerator pedal. Avoid excessive
engine speeds and shift to the next
higher gear at an early point. On down-
grades or slopes, shift down to the next
lower gear at an early point. Maintain an
adequate distance between yourself
and the vehicle ahead.BrakesWinter road conditions substantially
reduce the traction available between
the tires and the road surface.
Remember that braking distances will
be significantly longer as a result.
ABS is intended to prevent the wheels
from locking during brake applications,
thus helping to maintain vehicle stability
and steering response.
If the ABS does not respond in a critical
braking situation and the wheels lock:
Reduce the pressure on the brake pedal
until the wheels just start to roll again
while still maintaining enough force to
continue braking.
Following that, increase pedal pressure
again. Reduce the pressure as the
wheels lock, then reapply pressure.
Repeat this procedure. This type of
staggered braking will reduce the
braking distance, and the vehicle still
remains responsive to steering. It allows
you to steer around hazards once you
have reduced the pressure on the brake
pedal.

123n
IndexDataTechnologyRepairsCar careControlsOverview
Winter operation Power steering
Do not shift down on slick road
surfaces. Doing so could cause
the rear wheels to lose traction and
skid, resulting in a loss of vehicle
control.<
Depress the clutch during hard
braking on road surfaces that
provide only poor or uneven traction.<
Skid control Depress the clutch and release the
accelerator pedal, or place the selector
lever of the automatic transmission into
the "Neutral" position. Countersteer
carefully and attempt to regain control
of the vehicle.
ParkingEngage 1st or reverse gear. If your
vehicle is equipped with an automatic
transmission, place the selector lever in
Park. On vehicles with manual trans-
mission, also apply the parking brake
when parking on inclined surfaces. In
order to prevent the parking brake
linings from locking due to frost or
corrosion, dry them by gently applying
the parking brake as the vehicle is
coming to a stop. Make sure that
following traffic is not endangered.
The brake lamps do not light up
when the parking brake is
applied.<
If the steering response changes, e.g.
high steering effort:
Contact a BMW center to have this
system inspected.
If the power steering fails,
increased effort will be required to
steer the vehicle.<

126n
To maintain good handling and vehicle
response, use only tires of a single
tread configuration from a single manu-
facturer. BMW tests and approves
wheel/tire combinations, beginning on
page 130.
DOT Quality GradesTreadwear
Traction AA A B C
Temperature A B C
All passenger vehicle tires must
conform to Federal Safety
Requirements 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 (1g) 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.
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 vehicle 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, underinflation, 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
Do not use retreaded tires. Driving
safety may be impaired by their
use. This is due to the possible varia-
tions in casing structures and, in some
cases, to their extreme age, factors that
can lead to a decrease in their dura-
bility.<
Tire replacement

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IndexDataTechnologyRepairsCar careControlsOverview
Tire replacement Tire rotationTire ageThe date on which the tire was manu-
factured is indicated by the code on the
sidewall:
DOT ... 4100 means that the tire was
manufactured in week 41 of 2000.
BMW 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.
Spare tires over 6 years old should be
used only in case of emergency. A tire
in this condition should be replaced by
a new tire immediately, and should not
be mounted together with new tires.
Between the axlesThe tread wear patterns at the front end
differ from those at the rear Ð the actual
patterns will vary according to indi-
vidual driving conditions. In the inter-
ests of safety and maintaining optimal
handling characteristics, tire rotation is
not recommended.
If a proposed interaxle rotation of tires
is based on economic considerations,
one should consider whether the costs
for the rotation are likely to be recap-
tured by any increase in the service life
of the tires that might be realized. In
principle, interaxle rotation must be
performed in short intervals, with a
maximum of 3,000 miles (5,000 km).
Consult your BMW center for more
information.
Should you decide to rotate the tires, it
is essential to comply with the following:
Rotate tires on the same side only, since
braking characteristics and road grip
could otherwise be adversely affected.
Following rotation, the tire inflation
pressure should always be corrected.If different tire sizes are mounted
on the front and rear axles (refer to
page 130), the wheels may not be
rotated from one axle to the other.<

128n
Wheel and tire combinations The right choice Use only BMW-approved tires. Refer to
page 130.
Due to the high speeds this vehicle can
reach, the use of specific brands, spec-
ifications and sizes is mandatory.
Consult any BMW center for details.
Comply with local/national regulations.
The correct wheel-tire combina-
tion affects different systems such
as ABS, ATC and ASC+T/DSC. The
function of these systems is impaired if
improper wheel-tire combinations are
used.
For this reason, use only tires of the
same brand and tread pattern. In the
event of a flat tire, for example, remount
the approved wheel-tire combination as
soon as possible.<
Codes on tires and wheels The tire codes will aid you in selecting
the correct tire.
The codes on radial tires:
The speed rating indicates the approved
maximum speed for the tire.
Summer tires:
S = up to 112 mph (180 km/h)
T = up to 118 mph (190 km/h)
H = up to 130 mph (210 km/h)
V = up to 150 mph (240 km/h)
W = up to 167 mph (270 km/h)
Y = up to 187 mph (300 km/h)
ZR = above 150 mph (240 km/h) Example:
Nominal width
in mm
Aspect ratio in %
Radial tire ID code
Rim diameter in inches
Load rating
(not on ZR tires)
Speed rating
(before R on ZR tires)
205/60 R
1591W
Winter tires and all-season tires:
Q M+S = up to 100 mph (160 km/h)
T M+S = up to 118 mph (190 km/h)
H M+S = up to 130 mph (210 km/h)
Codes stamped on light-alloy wheels:
Protect tire valve from dirt by using
screw-on valve stem caps. Dirt in the
valves frequently leads to slow leaks. Example:
Rim width
in inches
Code letter for
flange type
Symbol for full-drop
center rim
Rim diameter in inches
Hump on the 2 rim shoulders
7 x 15 H 2
J

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IndexDataTechnologyRepairsCar careControlsOverview

Winter tires

Choosing the right tire

BMW recommends winter tires (M+S
radial tires) for driving in adverse winter
road conditions. Although all-season
M+S tires provide better winter traction
than standard summer tires with H, V,
W, Y and ZR speed ratings, they gener-
ally fail to provide the same levels of
performance as standard snow tires in
winter driving.
In the interest of safe tracking and
steering response, install winter tires
made by the same manufacturer having
the same tread configuration on all four
wheels.
Mount only winter tires approved by
BMW. Any BMW center will be glad to
provide you with information on the
best winter tires for your particular
driving conditions.

Do not exceed specified
maximum speeds

Never exceed the maximum speed
for which the tires are rated.
Unprofessional attempts by laymen to
service tires can lead to damage and
accidents.
Have this work performed by skilled
professionals only. Any BMW center
has the required technical knowledge
and the proper equipment and will be
happy to assist you.

<

Tire condition, tire pressure

Winter tires display a perceptible loss in
their ability to cope with winter driving
conditions once the tread wears to
below 0.16 inches (4 mm), and should
thus be replaced.
Comply with the specified tire inflation
pressures Ð and be sure to have the
wheel and tire assemblies balanced
every time you change the tires.

Storage

Always store tires in a cool, dry place.
Store them away from light whenever
possible. Protect the tires against
contact with oil, grease and fuel.

Snow chains

*
The use of narrow-link BMW snow
chains on winter tires is approved only
in pairs and only on the rear wheels.
BMW 325xi, 330xi: in a worst-case
scenario, if your vehicle is stuck on one
side or you cannot access one tire, then
a chain may be attached to one rear
wheel for a short period of time.
Comply with all manufacturer's safety
precautions when mounting the chains.