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Uniform tire quality grading standards – Mercedes-Benz S-Class 2007 User Manual

Page 525

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524

Operation

Tires and wheels

Uniform Tire Quality Grading Standards
(U.S. vehicles)

Tire manufacturers are required to grade
tires based on three performance
factors: treadwear, traction and
temperature resistance.

1 Treadwear
2 Traction
3 Temperature resistance

Quality grades can be found, where appli-
cable, on the tire sidewall between tread
shoulder and maximum section width. For
example:

All passenger car tires must conform to
federal safety requirements in addition to
these grades.

Treadwear

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.

Warning!

G

Never exceed the max. tire inflation

pressure. Follow recommended tire inflation

pressures.

Do not underinflate tires. Underinflated tires

wear excessively and/or unevenly, adverse-

ly affect handling and fuel economy, and are

more likely to fail from being overheated.

Do not overinflate tires. Overinflated tires

can adversely affect handling and ride com-

fort, wear unevenly, increase stopping dis-

tance, and result in sudden deflation

(blowout) because they are more likely to

become punctured or damaged by road de-

bris, potholes etc.

i

For illustration purposes only. Actual data

on tires are specific to each vehicle and may vary
from data shown in above illustration.

Treadwear Traction

Temperature

200

AA

A