Mercedes-Benz 2009 R-Class, Operator'S Manual

Page: 256 / 412

Tires and wheels
254
Replace the tire if you find any of the above
conditions.
Make sure you also inspect the spare tire
periodically for condition and inflation. Spare
tires will age and become worn over time even
if never used, and thus should be inspected
and replaced when necessary.
Life of tire
G
Warning!
Tires and spare tire should be replaced
after 6 years, regardless of the remaining
tread.
The service life of a tire is dependent upon
varying factors including but not limited to:
R
Driving style
R
Tire inflation pressure
R
Distance driven
Tread depth
G
Warning!
Although the applicable federal motor
vehicle safety laws consider a tire to be
worn when the treadwear 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 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 approximately
1
/
16
in (1.6 mm), at which point the tire is
considered worn and should be replaced.
The recommended minimum tire tread depth
for summer tires is
1
/
8
in (3 mm). The
recommended minimum tire tread depth for
winter tires is
1
/
6
in (4 mm).
1
TWI ( Tread Wear Indicator)
The treadwear indicator appears as a solid
band across the tread.
Storing tires
! 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.
Cleaning tires
!
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.
Operation