1998 BMW CONVERTIBLE technical data

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Failure of one brake circuitPedal travel increases, more pressure is
required at the pedal.
The remaining circuit continues to pro-
vide good braking response.a
In the event of any malfunction in
the brake system, consult the nearest
BMW Retailer as soon as possible.cThe 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.
CoolantEnsure that the coolant contains the
year-round 50:50 ratio of water and
antifreeze with corrosion inhibitor. This
mixture provides protection against
freezing down to approximately -345F
(-376). Replace the coolant every
three years.Lockscan be made operative again using
BMW lock de-icer. This de-icer also
contains lubricants.
In addition, a treatment with BMW lock
cylinder 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.b
A complete range of car-care
products is available from any autho-
rized BMW Retailer.c
Snow chainsBMW snow chains
* can be mounted on
both summer and winter tires. Mount
them in pairs on the rear wheels only
and observe the manufacturer's safety
precautions. Do not exceed a maximum
speed of 30 mph (50 km/h). For maxi-
mum traction, deactivate ASC+T when
driving with snow chains mounted, refer
to page 84.
Starting offWhen driving off in deep snow or "rock-
ing" the vehicle to free it, you should
switch off ASC+T, refer to page 84. Driving on low-traction road
surfacesOperate the accelerator pedal sensi-
tively, avoid high engine speeds and
shift up to the next-higher gear early.
Shift down into the next lowest gear
when approaching uphill or downhill
grades. Maintain an adequate distance
between yourself and the car ahead.
Brake system Winter driving

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A special luggage system is available as
an option for your BMW. Please
observe the precautions included with
the installation instructions.
Because roof racks raise the center of
gravity of the car when loaded, they
exercise a major effect on its handling
and steering response.
You should therefore always remember
not to exceed the approved roof weight,
the approved gross vehicle weight or
the axle weights when loading the rack.
For specifications refer to "Technical
data", page 163ff.
Make sure that the load is not too heavy,
and attempt to distribute it evenly.
Always load the heaviest items first (on
the bottom).
Make sure there is sufficient space to
raise the sliding/tilt sunroof.Secure the roof luggage correctly and
securely to prevent it from shifting or
being lost during driving (danger to fol-
lowing traffic).
Drive smoothly: avoid sudden accelera-
tion and braking maneuvers; corner
gently.
The roof load increases the surface
area exposed to the wind: increased
fuel consumption and stress on the roof
are the immediate results.Roof-mounted luggage rack*

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Even in winter, when the hardtop may
be in constant use, the fabric top does
not need to be removed. Before storing
the fabric top in the convertible top
compartment, it must be absolutely dry
to prevent the formation of water and
mildew spots.
Two persons are required for mounting
and removal. Use extreme care when
working to prevent paint damage and
damage to the body and hardtop.
To make it easier to mount and remove
the hardtops, you can purchase a spe-
cially developed hardtop lift
* from your
BMW Retailer.
MountingLower the side windows and remove
the rod antenna if necessary to prevent
damage.
Unlock the convertible top compart-
ment lid on vehicles with manual con-
vertible top operation, or open the con-
vertible top compartment lid slightly
with the convertible top operating but-
ton on vehicles with electric convertible
top operation, as illustrated.
Remove the trim pieces on both sides
and then close the convertible top com-
partment lid again.Before positioning the hardtop on the
car, fold down the covers below the
interior lamps at the left and right and
open the locking levers outward.
Now, with somebody elseÕs help, posi-
tion the hardtop on the mounts.
Close the locking lever at the back by
turning it inward (arrow) up to the stop
behind the trim.
As with the fabric top, fold out the lock-
ing handle inside and lock the hardtop
at the front by turning the handle until it
audibly engages.36cde018
36cde019
Hardtop* Ð Convertible

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Information for your safetyThe factory-approved radial tires have
been selected to provide optimum
safety and driving comfort on your vehi-
cle.
In a very real sense, both tire life and
your own safety are riding on correct
tire specifications and inflation pres-
sures.
Incorrect inflation pressures are a fre-
quent cause of tire damage. To a great
extent it also influences the ability of
your BMW to hold the road.a
Check the tire pressures Ð also in
the spare tire Ð at least every two weeks,
and before every extended trip.
Incorrect inflation pressures can also
lead to tire damage and accidents.c
Tire tread - tire damageInspect your tires frequently for tread
wear, signs of damage and for foreign
objects lodged in the tread. Check the
tread depth.
The tread depth should not be less than
0.12 in (3 mm). Otherwise there is an
increased risk of aquaplaning, even at
relatively moderate speeds and with
only small amounts of water on the
road.
We recommend that you always replace
the tires once the tread wears to 0.12 in
(3 mm). Once the tread has worn to
0.063 in (1.6 mm), tread depth indica-
tors appear.a
Never continue driving on a deflat-
ed (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. This can cause overheating and
gradual internal damage. 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
response, such as a pronounced ten-
dency to pull to the left or right. Should
this occur, you should respond by
immediately reducing your speed and
carefully proceeding to the nearest
BMW Retailer or professional tire cen-
ter, 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.c
Tire inflation pressures Tire tread

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Tires and wheelsUse only BMW-approved tires.
Due to the high speeds which this vehi-
cle can reach, the use of specific
brands, specifications and dimensions
is mandatory. Consult any BMW
Retailer for details.
Observe national, provincial and state
regulations.
The tire codes will aid you in selecting
the correct tire. The essential data for
radial tires are as follows: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 149 mph (240 km/h)
W = up to 167 mph (270 km/h)
ZR = over 149 mph (240 km/h)
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)
Use screw-on valve stem caps to
protect the tire valves against dirt. Dirt
in the valves frequently leads to slow
leaks.Example:Nominal width
in mm
Aspect ratio in %
Type of radial-code
letter for radial
Rim diameter in inches
Load rating
(not on ZR tires)
Speed rating
(before R on ZR tires)
205/60 R 15 91 H
Codes on steel/light-alloy wheels:
7 J x 15 H 2
Hump width (inches)
Code letter for
flange type
Denotes
drop-center rim
Rim diameter (inches)
Hump of 2 rim shoulders
The right choice

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b
Size 185/65 R 15 88 T tires are
only for the BMW 318i Sedan.c
b
Sizes 225/55 R 15 92 V,
225/55 R 92 Q, T, H M+S, 225/50 ZR 16.
These tires are not suitable for use with
snow chains.c
ModiÞcations to the vehicle are required
before retrofitting tires in the above
dimensions.
Please consult your BMW Retailer.The use of fine-link BMW snow chains
*
on summer or winter tires is only per-
mitted in pairs on the rear wheels.
Always observe the tire manufacturerÕs
safety recommendations when fitting. Tire speciÞcations Steel rim
(wheel rim)Light-alloy wheel Rim offset
(mm)
BMW 318is Coupe, 318i Convertible, 318i Sedan
185/65 R 15 88 T 6 J x 15 H2 Ð 42
185/65 R 15 88 Q, T M+S
6 J x
15 H2
Ð42
205/60 R 15 91 H
6g Jx15 H2
7 J x 15 H2 47
205/60 R 15 91 Q, H M+S
6g Jx15 H2
7 J x 15 H2 47
225/55 R 15 92 V
6g Jx15
H2 7 J x 15 H2 47
225/50 R 16 92 Q M+S Ð 7 J x 16 H2 45/46
225/50 ZR 16 Ð 7 J x 16 H2 45/46
Approved wheels and tires

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b
Size 225/50 ZR 16 tires are not
suitable for use with snow chains.c
ModiÞcations to the vehicle are required
if retrofitting these tires.
Please consult your BMW Retailer.The use of fine-link BMW snow chains
*
on summer or winter tires is only per-
mitted in pairs on the rear wheels.
Always observe the tire manufacturerÕs
safety recommendations when fitting. Tire speciÞcations Steel rim
(wheel rim)Light-alloy wheel Rim offset
(mm)
BMW 328is Coupe, 328i Convertible, 328i Sedan
205/60 R 15 91 H Ð 7 J x 15 H2 47
205/60 R 15 91 Q, H M+S
6g Jx15 H2
7 J x 15 H2 47
225/50 R 16 92 Q M+S Ð 7 J x 16 H2 45/46
225/50 ZR 16 Ð 7 J x 16 H2 45/46
Approved wheels and tires

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