Mercedes-Benz S-Class 2011 - Manual (Page 497)

Tread wear
The tread wear grade is a comparative rating
based on the wear rate of the tire when tested
under controlled conditions on a specified
U.S. government test track. For example, a
tire graded 150 would wear one and one-half
times as well on the government test track as
a tire graded 100.
The relative performance of tires depends
upon the actual conditions of their use,
however, and may depart significantly from
the norm due to variations in driving habits,
service practices and differences in road
characteristics and climate conditions.
Traction
G
Warning
The traction grade assigned to this tire is
based on straight-ahead braking traction
tests, and does not include acceleration,
cornering, hydroplaning, or peak traction
characteristics.
The traction grades, from highest to lowest,
are AA, A, B, and C. These grades represent
the tire's ability to stop on a wet surface as
measured under controlled conditions on
specified government test surfaces of asphalt
and concrete. A tire marked C may have poor
traction performance.
G Warning
If ice has formed on the road, tire traction will
be substantially reduced. Under such weather
conditions, drive, steer and brake with
extreme caution.
The safe speed on a wet, snow covered or icy
road is always lower than on dry road
surfaces.
You should pay special attention to road
conditions when temperatures are around
the freezing point.
Mercedes-Benz recommends a minimum tire
tread depth of 1/6 in (4 mm) for all four winter
tires ( Y page 482) to maintain normal driving
characteristics in winter. Winter tires can
reduce the braking distance on snow covered
surfaces in comparison to summer tires. The
braking distance is still much further than on
surfaces that are not icy or snowy. Take
appropriate care when driving.
! Avoid wheelspin. This can lead to damage
to the drive train.
Temperature
G
Warning
The temperature grade for this tire is
established for a tire that is properly inflated
and not overloaded. Excessive speed,
underinflation, or excessive loading, either
separately or in combination, can cause
excessive heat build-up and possible tire
failure.
The temperature grades are A (the highest),
B, and C, representing the tire's resistance to
the build up of heat and its ability to dissipate
heat when tested under controlled conditions
on a specified indoor laboratory test wheel.
Sustained high temperature can cause the
material of the tire to degenerate and reduce
tire life. Furthermore, excessive temperature
can lead to sudden tire failure. Grade C
corresponds to a level of performance which
all passenger car tires must meet under the
Federal Motor Vehicle Safety Standard No.
109. Grades B and A represent higher levels
of performance on the laboratory test wheel
than the minimum required by law.
Tire labeling
Tire labeling overview
The following markings are on the tire in
addition to the tire name (sales designation)
and the manufacturer's name:
Tire labeling
495
Tires and wheels
Z