Mercedes-Benz Metris Operator's Manual page 211

1
Tread wear grade
2
Traction grade
3
Temperature grade
%
The data shown in the illustration is sample
data.
%
This grading is not legally prescribed for Can-
ada, but speci ed in most cases anyway.
T T r r ead w ead wear gr ear grade ade
The tread wear grade is a comparative grading
based on tread wear grade tests conducted under
controlled conditions on a speci ed U.S. Depart-
ment of Transportation 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 gra-
ded 100.
The relative performance of tires depends upon
the actual conditions of their use, however, and
may depart signi cantly from the norm due to var-
iations in driving habits, service practices and dif-
ferences in road characteristics and climate condi-
tions.
Tr Traction gr action grade ade
& D D AN
ANGER GER Risk of accident due to inade-
quate traction
The traction grade assigned to this tire is
based on straight-ahead braking traction tests.
Always adapt your driving style and drive
#
at a speed to suit the prevailing tra c
and weather conditions.
* N N O O TE TE Damage to the drivetrain from
wheelspin
Avoid wheelspin.
#
The traction grades – from highest to lowest – are
AA, A, B and C. These grades relate to the tire's
ability to come to a standstill on a wet pavement
under controlled conditions on a speci ed U.S.
Wheels and tires 209
government test surface made from asphalt and
concrete.
T T em emper peratur ature gr e grade ade
& W W ARNING
ARNING Risk of accident from tire over-
heating and tire failure
Excessive speed, underin ation, or excessive
loading, either separately or in combination,
can cause excessive heat build-up and possible
tire failure.
Observe the recommended tire pressure.
#
Regularly check the pressure of all the
#
tires.
Adjust the tire pressure, if necessary.
#
The temperature grades are A (highest grade), B
and C. These relate to a tire's resistance to heat
and its ability to release heat on a speci ed test
wheel in laboratory tests under controlled condi-
tions. Sustained high temperatures can cause the
material of the tire to degenerate and reduce tire
life. In addition, excessively high temperatures can
lead to sudden tire failure. Grade C refers to a per-
formance which all passenger vehicle tires must
exhibit, according to the U.S. Department of Trans-
portation's requirements.
Inf Infor ormation on DO mation on DOT and TIN (T T and TIN (Tir ire e Identi cation
Number) Number)
U.S. tire regulations indicate that every tire manu-
facturer or retreader must imprint a TIN in or on
the sidewall of each tire produced.
%
The data shown in the illustration is sample
data.
The TIN is a unique identi cation number for tires
and consists of the following components:
DO DOT (Depar T (Department of Tr tment of Transport ansportation):
R
bol 1 indicates that the tire complies with the
209
Identi cation
ation): tire sym-