334 OperationTires and wheelsTreadwear
The treadwear grade is a comparative rat-
ing based on the wear rate of the tire when
tested under controlled conditions on a
specified government test course. For ex-
ample, a tire graded 150 would wear one
and one-half (1
1/2) times as well on the
government course 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.Traction
The traction grades, from highest to low-
est, are AA, A, B, and C. Those grades rep-
resent the tire’s ability to stop on wet
pavement as measured under controlled
conditions on specified government test
surfaces of asphalt and concrete. A tire
marked C may have poor traction perfor-
mance.Temperature
The temperature grades are A (the high-
est), B, and C, representing the tire’s resis-
tance to the generation of heat and its
ability to dissipate heat when tested under
controlled conditions on a specified indoor
laboratory test wheel. Sustained high tem-
perature can cause the material of the tire
to degenerate and reduce tire life, and ex-
cessive temperature can lead to sudden
tire failure. The grade C corresponds to a
level of performance which all passenger
car tires must meet under the Federal Mo-
tor 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.
Warning!
G
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.
358 Practical hintsWhat to do if …?Problem
Possible cause
Suggested solution
v
The yellow ESP warning lamp
comes on while driving.
The ESP is deactivated.
Risk of accident!
Adapt your speed and driving to the prevail-
ing road conditions.
Switch the ESP back on (
page 88).
If the ESP cannot be switched back on,
have the system checked at an autho-
rized Mercedes-Benz Center as soon as
possible.
v
The yellow ESP warning lamp
flashes while driving.
The ESP or traction control has come into
operation because of detected traction loss
in at least one tire.
When driving off, apply as little throt-
tle as possible.
While driving, ease up on the acceler-
ator.
Adapt your speed and driving to the
prevailing road and weather condi-
tions.
Do not deactivate the ESP.
Exceptions: (
page 87).
Failure to follow these instructions in-
creases the risk of accidents.
