1998 BMW 740I tires

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To ensure that your vehicle provides
maximum economy throughout a long
service life, we request that you comply
with the following:
Engine and differentialUp to 1,200 miles (2,000 km):
Drive at varying engine speeds and
road speeds, but do not exceed
4500 rpm and/or 105 mph (170 km/h)
during this initial period. Comply with
the legal speed limit at all times.
Refrain from using full throttle and avoid
pressing the accelerator beyond the
kickdown point.
Once 1,200 miles (2,000 km) have
elapsed, engine speeds and road
speeds can gradually be increased.
You should also comply with these
break-in procedures if the engine or dif-
ferential is replaced later in the course
of the vehicle service life.TiresDue to technical factors associated with
their manufacture, tires do not achieve
their full traction potential until an initial
break-in period has elapsed.
Thus drive with extra care during the
initial 200 miles (300 km).When the vehicle is operated on
wet or slushy roads, a wedge of
water may form between the tire and
the road surface. This phenomenon is
referred to as aquaplaning, or hydro-
planing, and can lead to partial or com-
plete loss of traction, vehicle control
and braking effectiveness. Reduce your
speed on wet roads.<
Brake systemApproximately 300 miles (500 km) must
elapse before the brake pads and rotors
achieve the optimal pad-surface and
wear patterns required for trouble-free
operation and long service life later on.
To break-in the separate parking brake
drums, apply the parking brake lightly
when coasting to a standstill (at a traffic
signal, for instance), provided that traf-
fic conditions allow you to do so.
To avoid corrosion, repeat this proce-
dure from time to time.
The brake lamps do not come on
when the parking brake is applied.
Vacuum for the brake system servo unit
on your BMW is available only when the
engine is running. When you move the
car with the engine shut off – when tow-
ing, for instance – substantially higher
levels of pedal force will be required to
brake the vehicle.<
Break-in procedure

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RepairsIndexOverview Controls Car care Technology Data
Driving notes
Brakes:
Do not drive with your foot resting
on the brake pedal. Even light but con-
sistent pedal pressure can lead to high
temperatures, brake wear and possibly
even brake failure.
Aquaplaning:
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 is
referred to as aquaplaning or hydro-
planing. It is characterized by a partial
or complete loss of contact between
the tires and the road surface. The ulti-
mate results are loss of steering and
braking control.
Driving through water:
Do not drive through water more than
1 foot (30 cm) deep. In water of this
depth, drive only at walking speed, oth-
erwise damage to the engine, the elec-
trical system and the transmission can
occur.
Rear parcel tray:
Do not use the rear parcel tray to store
heavy or bulky objects. They could
pose a danger to the occupants during
braking maneuvers.
Clothes hooks:
Hang items of clothing from the hooks
so that they will not obstruct the driver's
vision. In order to avoid personal inju-
ries during braking maneuvers, do not
hang heavy objects on the hooks.<

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RepairsIndexOverview Controls Car care Technology Data
Antilock Brake System (ABS)The conceptABS enhances active safety by helping
to prevent the wheels from locking dur-
ing brake applications. The reason:
Locked wheels are dangerous. When
the front wheels slide, the driver loses
steering control over the vehicle. Trac-
tion loss at the rear wheels can cause
the rear end to break into an uncon-
trolled skid.
The system can achieve the shortest
braking distances possible under most
conditions (on straights 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 – on all types of road
surfaces (asphalt, concrete, mud, wet
pavement, snow, ice).
Braking with ABSThe system becomes operative once
the vehicle exceeds a speed of approx.
6 mph (10 km/h). The ABS is deactivated
whenever the vehicle's speed drops
back below approx. 4 mph (6 km/h). This
means that the wheels can lock in the fi-
nal phase of a panic stop – a factor of no
significance in actual use.
If you are in a situation which requires
full braking, you will exploit the full bene-
fits of the ABS system if you apply maxi-
mum brake pressure ("panic stop").
Since the vehicle maintains steering re-
sponsiveness, you can avoid possible
obstacles with a minimum of steering ef-
fort, despite the full brake application.
The ABS system closed-loop control cir-
cuit cycles in fractions of a second.
A pulsation at the brake pedal indicates
to the driver that ABS is active, that is,
that the vehicle is within its maximum
braking range. In addition, a pulsation – a
result of the control function cycles – in-
dicates to the driver that vehicle speed
should be reduced to adapt to road sur-
face conditions when there is reduced
traction and grip between tires and road
surface (slippery road surface).
Always depress the brake pedal with
constant pressure. Keep the brake pedal
down. Do not pump the brakes.In driving conditions where there is a
loose upper surface together with a
subsurface which provides better trac-
tion (on gravel or snow, for instance), or
with snow chains, the braking distance
may also be longer than when the
wheels are locked. However, ABS con-
tinues to provide enhanced vehicle sta-
bility and steering response under
these conditions.
Information for your safetyNot even ABS can suspend the laws of
physics. ABS alone cannot prevent ac-
cidents when the brakes are applied
without an adequate safety interval be-
tween vehicles, if the car is driven at an
excessive rate of speed in curves, or if
aquaplaning occurs. Responsibility for
these types of situations remains in the
hands (and at the feet) of the driver. You
should never allow the added safety of
ABS to lull you into a false sense of se-
curity, or mislead you into taking in-
creased risks that could affect your own
safety and that of others.
Do not make any modifications to
the ABS system.
Service procedures on ABS are to be
performed by authorized technicians
only.<

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RepairsIndexOverview Controls Car care Technology Data
Winter operationRubber seals and componentsIn order to prevent the weather-strip-
ping from freezing, apply rubber treat-
ment or a silicone spray to the seals on
the doors, hood and luggage compart-
ment lid.
A full range of car care products is
available from your BMW center.< Snow chainsBMW snow chains
* can be fitted on
both summer and winter tires in re-
sponse to severe winter road condi-
tions. Mount them in pairs on the rear
wheels only, and be sure to comply with
the manufacturer's safety instructions.
Do not exceed a maximum speed of
30 mph (50 km/h). In this situation
(snow chains mounted), deactivate the
ASC+T or DSC
*. Refer to page 92.
Starting offWhen starting off in deep snow or when
rocking the car to free it, we recom-
mend that you switch the ASC+T or
DSC
* off. Refer to page 92.
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. Adapt
your speed and driving style when ap-
proaching grades. Maintain an ade-
quate distance between yourself and
the car ahead.BrakesWinter road conditions substantially re-
duce the amount of traction available
between the tires and the road surface;
the resulting increases in braking dis-
tance are considerable and should be
continually borne in mind.
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, etc.
This type of staggered braking will re-
duce the braking distance, and the ve-
hicle still remains responsive to steer-
ing.
You can then attempt to steer around
hazards after you have reduced pres-
sure on the brake pedal.
Do not shift down on slick road
surfaces. Doing so could cause
the rear wheels to lose traction and
skid, which could result in the loss of
vehicle control.<

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Tire inflation pressure Tire conditionInformation for your safetyThe factory-approved radial tires are
matched to the car and have been se-
lected to provide optimum safety and
driving comfort on your car.
It is not merely the tire's service life, but
also driving comfort and - above all else
- driving safety which depend on the
condition of the tires and the mainte-
nance of the specified tire pressure.
Incorrect inflation pressure is a frequent
cause of tire damage. They also influ-
ence the roadholding ability of your
BMW.
Check tire inflation pressures – in-
cluding the spare tire – regularly,
at least every two weeks and before be-
ginning a longer trip. If this is not done,
incorrect tire pressures can cause driv-
ing instability and tire damage, ulti-
mately resulting in accidents.<
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 0.12 in (3 mm), even though
the legally specified minimum tread
depth is only 0.063 in (1.6 mm). Wear
indicators appear in the tread at 0.063 in
(1.6 mm) to indicate that the legally per-
missible wear limit has been reached.
Below 0.12 in (3 mm) tread depth, there
is an increased risk of aquaplaning,
even at relatively moderate speeds and
with only small amounts of water on the
road.390de331
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 ex-
ceeded. Overloading can lead to over-
heating and increases the rate at which
damage develops 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 defect,
as can variations in normal vehicle re-
sponse, such as a pronounced ten-
dency to pull to the left or right. Should
this occur, respond by immediately re-
ducing your speed and carefully pro-
ceeding to the nearest BMW center or
professional tire center, or having the
vehicle towed in to have it and its tires
inspected.
Tire damage (up to and including blow-
outs) can endanger the lives of both the
vehicle occupants and other road
users.<

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Tire replacement Tire rotationTo 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. Refer to
page 136.
Do not use retreaded tires, since
driving safety may be impaired by
their use. This is due to the possible
variations in casing structures and, in
some cases, to their extreme age,
which can lead to a decrease in their
durability.< Tire ageThe date on which the tire was manu-
factured is indicated by the code on the
sidewall:
DOT ... 178 means that the tires were
manufactured in the 17th week of 1998.
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. Such a
tire 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 - the actual
patterns will vary according to individ-
ual driving conditions. In the interests of
safety and maintaining optimal handling
characteristics, tire rotation is not rec-
ommended.
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 which might be realized. Ro-
tation should always be carried out at
short intervals, with a maximum of
3,000 miles (5,000 km). Consult your
authorized BMW center for more infor-
mation.
Should you decide to rotate the tires, it
is essential to comply with the follow-
ing:
Rotate tires on the same side only,
since braking characteristics and road
grip could otherwise be adversely af-
fected.
Following rotation, correct the tire infla-
tion pressure.If different tire sizes are mounted
on the front and rear axles
(page 136), the tires may not be rotated
from one axle to the other.<

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Wheel and tire combinationsThe right choiceUse only tires approved by BMW. Refer
to page 136.
Because of the high speeds this vehicle
can reach, the use of specific tire
brands, specifications and dimensions
is mandatory. Consult any BMW center
for details.
Comply with national, state, or provin-
cial regulations.
The correct wheel-tire combina-
tion affects different systems such
as ABS, ATC, ASC+T/DSC. The func-
tion of these systems is impaired if im-
proper 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 if you have mounted
winter tires, for example, remount the
approved wheel-tire combination as
soon as possible.<
Codes on tires and wheelsThe tire codes will aid you in selecting
the correct tire.
Codes on radial tires:
The speed rating indicates the ap-
proved 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 149 mph (240 km/h)
W = up to 167 mph (270 km/h)
ZR = over 149 mph (240 km/h) For example
Nominal width
in mm
Aspect ratio in %
Radial tire code
Rim diameter in inches
Load rating
(not on ZR tires)
Speed rating
(before R on ZR tires)
235/60 R 16 100 W
Winter 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 valve inserts against dirt using
screw-on valve stem caps. Dirt in the
valves frequently leads to slow leaks.For 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
71/2 x 16 H 2
J

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RepairsIndexOverview Controls Car care Technology Data
Winter tires Snow chains
*
Choosing the right tireBMW recommends winter tires (M+S
radial tires) for driving in adverse winter
road conditions. While tires known as
all-season tires (M+S designation) pro-
vide better winter traction than summer
tires with load ratings H, V, W and ZR,
they generally do not achieve the per-
formance of winter tires.
In the interests of sure tracking and safe
steering response at all four wheels,
mount winter tires which are made by
the same manufacturer and which have
the same tread configuration.
Mount only winter tires which have
been 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 pressureWinter tires display a perceptible loss in
their ability to cope with winter driving
conditions once the tread wears to be-
low 0.16 in (4 mm), and should thus be
replaced.
Comply with the specified tire inflation
pressures - and be sure to have the
wheel and tire assemblies balanced ev-
ery time you change the tires.StorageStore tires in a cool, dry place, away
from light whenever possible. Protect
the tires against contact with oil, grease
and fuel.
Use narrow-link BMW snow chains on
summer or winter tires only in pairs and
only on the rear wheels. Comply with all
manufacturer's safety precautions when
mounting the chains.