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:
Safety
The BMW 1 Series hasn't been crash-tested. It includes frontal, front-seat
side-impact and side curtain airbags. Also standard are antilock brakes and an
electronic stability system with traction ...
System limits
Personal responsibility
The system cannot serve as a substitute
for the driver's personal judgment of the traffic
situation.
In the event of a warning, do not jerk the steering
wheel, as ...
Fuel quality
Fuels that are marked on the gas pump as containing
metal must not be used.
Refuel only with unleaded gasoline without
metallic additives.
Do not refuel with any leaded gasoline or gasoline
with ...
