Tire tread
Summer tires
Do not drive with a tire tread depth of less than 0.12 in/3 mm.
There is an increased danger of hydroplaning if the tread depth is less than 0.12 in/3 mm.
Winter tires
Do not drive with a tire tread depth of less than 0.16 in/4 mm.
Below a tread depth of 0.16 in/4 mm, tires are less suitable for winter operation.
Minimum tread depth

Wear indicators are distributed around the tire's circumference and have the legally required minimum height of 0.063 in/1.6 mm.
They are marked on the side of the tire with TWI, Tread Wear Indicator.
See also:
Personal Profile settings
The following functions and settings can be
stored in a profile.
More information on the settings can be found
under:
Active Cruise Control: collision warning.
Exterior mirror position.
C ...
BMW Maintenance System
The BMW Maintenance System supports the preservation of the traffic and operating
safety of your BMW. The objective is to optimize efforts with respect to minimal
vehicle maintenance costs.
If ...
Visual warning
The approach of the vehicle to an object can be
shown on the Control Display.
When the distance to an object is small, a red bar
is shown in front of the vehicle, as it is in the PDC
display.
...
