Mercedes-Benz R-Class 2008 Owners Manual - Manual (Page 366)

365
Operation
Tires and wheels
Tread depth
Do not allow your tires to wear down too
far. Adhesion properties on wet roads are
sharply reduced at tread depths of less
than
1 /
8
in (3 mm).
Treadwear indicators (TWI) are required by
law. These indicators are located in six
places on the tread circumference and
become visible at a tread depth of approx-
imately
1 /
16
in (1.6 mm), at which point the
tire is considered worn and should be re-
placed.
Recommended minimum tire tread depth:
ț Summer tires 1 /
8
in (3 mm)
ț Winter tires 1 /
6
in (4 mm)
1 TWI (Tread Wear Indicator)
The treadwear indicator appears as a solid
band across the tread.
Storing tires
Cleaning tires
Direction of rotation
Unidirectional tires offer added advan-
tages, such as better hydroplaning perfor-
mance. To benefit, however, you must
make sure the tires rotate in the direction
specified.
An arrow on the sidewall indicates the
intended direction of rotation (spinning) of
the tire.
Warning!
G
Although the applicable federal motor safety
laws consider a tire to be worn when the
treadwear indicators (TWI) become visible at
approximately 1 /
16
in (1.6 mm), we recom-
mend 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.
!
Keep unmounted tires in a cool, dry
place with as little exposure to light as possible.
Protect tires from contact with oil, grease and
fuels.
! Never use a round nozzle to power wash
tires. The intense jet of water can result in
damage to the tire.
Always replace a damaged tire.