Tire tread
WARNING
Although the applicable federal motor vehicle
safety laws consider a tire to be worn when
the tread wear indicators (TWI) become
visible at approximately 1/16 in (1.6 mm), we recommend that you do not allow
your tires
to wear down to that level. As tread depth
approaches 1/8 in (3 mm), the adhesion
properties on a wet road are sharply reduced.
Depending upon the weather and/or road surface (conditions), the tire traction varies widely.
Do not use tires that are excessively worn as the tire traction on wet road surfaces decreases significantly when the tread depth is less than 1/8 inch (3 mm).
Tread wear indicators (TWI) are required by law. Six indicators are positioned on the tire tread. They become visible as soon as a tread depth of approximately 1/16 inch (1.6 mm) has been reached. If this is the case, the tire is so worn that it must be replaced.
The recommended tread depth for summer tires is at least 1/8 inch (3 mm). The recommended tread depth for winter tires is at least 1/6 inch (4 mm).

Bar marking 1 for tread wear is integrated into the tire tread.
See also:
BAS PLUS (Brake Assist System Plus)
BAS PLUS is only available in vehicles
equipped with DISTRONIC PLUS.
Observe the "Important safety notes"
section
At speeds above approximately
4 mph (7 km/h), BAS PLUS assists you w ...
"Coupling up a trailer" function
This function is only available on vehicles with
a trailer tow hitch.
1 Center of the vehicle on the red guide line
approximately 10 in (0.25 m) away from
the rear area
2 Center of the vehic ...
Deactivating cruise control
There are several ways to deactivate cruise control:
Briefly press the cruise control lever forwards 3.
or
Brake.
Cruise control is automatically deactivated if:
you depress the park ...
