Consumer Information; Uniform Tire Quality Grading; Treadwear; Temperature “A”, “ B”, “C” - Mercedes-Benz 420 SEL 1989 Owner's Manual

Consumer Information

This has been prepared as required of
all manufacturers of passenger cars
under Title 49, Code of U.S. Federal
Regulations, Part 575 pursuant to the
" National Traffic and Motor Vehicle
Safety Act of 1966" .

Uniform Tire Quality Grading

Relevant tire grade information on tire
sidewalls.
All passenger car tires must conform
to federal safety requirements. In ad­
dition, consumer information on
treadwear, traction and temperature
must be provided.

Treadwear

The treadwear grade is a comparative
rating based on the wear rate of the
tire when tested under controlled con­
ditions on a specified government test
course. For example, a tire graded
150 would wear one and a half (11 / 2 )
times as well on the government
course as a tire graded 100. The rela­
tive performance of tires depends
upon the actual conditions of their
use, however, and may depart sig­
nificantly from the norm due to varia­
tions in driving habits, service prac­
tices and differences in road charac­
teristics and climate.
Traction "A" , " B" , "C"
The traction grades, from highest to
lowest, are "A" , " B" and "C" and they
represent 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 performance.
Warning!
The traction grade assigned to
this tire is based on braking
(straight ahead) traction tests
and does not include cornering
(turning) traction.
Temperature "A" , " B" , "C"
The temperature grades of "A" (the
highest). " B" and "C" representing
the tire's resistance to the genera­
tion 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, and
excessive temperature can lead to
sudden tire failure. The grade "C"
corresponds to a level of perfor­
mance 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 in the labora­
tory test than the minimum required
by law.
Warning!
The temperature grade for this
tire is established for a tire that is
properly inflated and not over­
loaded. Excessive speed, under­
inflation, or excessive loading,
either separately or in combina­
tion, can cause excessive heat
build up and possible tire failure.