tire type BMW 325Ci CONVERTIBLE 2001 E46 Owner's Manual

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IndexDataTechnologyRepairsCar careControlsOverview
Tire Pressure Control (RDC)
*
The conceptRDC monitors the tire pressures at all
four wheels, even when the vehicle is
moving. The system provides an alert
whenever the inflation pressure drops
significantly below the specified pres-
sure in one or more tires.
In order for the system to "learn" the
correct tire inflation pressure, check the
inflation pressure in all tires according
to the inflation pressure table (page 28)
and make corrections if necessary.
Then activate the system.
This indicator lamp in the instru-
ment cluster will inform you if
the tire pressure is not correct.
Activate the systemDepending on the type of equipment,
the switch either has the letters RDC on
it or the RDC-symbol.
1 Turn ignition key to position 2 (do not
start the engine).
2 Press the switch long enough for the
yellow indicator lamp in the instru-
ment cluster to light up for a few
seconds.
3 After a few minutes driving time, RDC
sets the current inflation pressure in
the tires as the target values to be
monitored.
You will only have to repeat this proce-
dure following a correction of the tire
inflation pressure. Otherwise, RDC
functions automatically when the igni-
tion key is in position 2, and thus oper-
ates whenever the vehicle is driven.46cus046
In the event of loss in tire
pressureIf the inflation pressure has dropped
significantly over a long period of time
(which is normal for any tire), the indi-
cator lamp will come on with a yellow
lamp.
This alerts you to have the tires inflated
to the specified pressures as soon as
possible.
If you are prompted to check the
tire pressure shortly after a
correction has been made, this indi-
cates that the corrected values were
not accurate. Please check the inflation
pressure again and make corrections
according to the inflation pressure
table. Then activate the system once
again.<

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IndexDataTechnologyRepairsCar careControlsOverview
Wheel and tire combinations The right choice Use only BMW-approved tires, begin-
ning on page 137.
Due to the high speeds this vehicle can
reach, the use of specific brands,
specifications and sizes is mandatory.
Consult any BMW center for details.
Comply with local/national regulations.
The correct wheel/tire combina-
tion has an effect on the different
systems such as ABS, ATC, ASC+T/
DSC
and ADB/DBC whose functioning
would be otherwise impaired if the
incorrect wheel/tire combinations were
used.
For this reason, use only tires of the
same manufacture and tread configura-
tion. In the event of a flat tire, for
example, remount the approved wheel/
tire combination as soon as possible.<
Codes on the 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 to112 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 = over 150 mph (240 km/h) Example:
Nominal width
in mm
Aspect ratio in X
Radial tire ID code
Rim diameter in inches
Load rating
(not on ZR tires)
Speed rating
(before R on ZR tires)
225/50 R
1692W
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 16 H 2
J