All About Wheels And Tires; Traction; Tread Wear; Uniform Tire Quality Grading Standards - Mercedes-Benz SLS AMG GT Coupe Operator's Manual

Gross axle weight rating: the maximum
permissible weight that can be carried by one
axle (front or rear axle).
To ensure that your vehicle does not exceed
the maximum permissible values (gross
vehicle weight and maximum gross axle
weight rating), have your loaded vehicle
(including driver, occupants, cargo, and full
trailer load if applicable) weighed on a
suitable vehicle weighbridge.

All about wheels and tires

Uniform Tire Quality Grading
Standards
Overview of Tire Quality Grading
Standards
Uniform Tire Quality Grading Standards are
U.S. government specifications. Their
purpose is to provide drivers with uniform
reliable information on tire performance data.
tire manufacturers have to grade tires using
three performance factors: tread wear :,
tire traction ; and heat resistance =. All
tires sold in North America are provided with
the corresponding quality class mark on the
sidewall of the tire, even though these
regulations do not apply to Canada.
Quality grades can be found, where
applicable, on the tire sidewall between the
tread shoulder and maximum tire width.
All about wheels and tires
Example:
Treadwear grade: 200
R
Traction grade: AA
R
Temperature grade: A
R
All passenger car tires must conform to the
statutory safety requirements in addition to
these grades.
i
The actual values for tires are vehicle-
specific and may deviate from the values in
the illustration.
Treadwear
The treadwear grade is a comparative rating
based on the wear rate of the tire when tested
under controlled conditions on a specified
U.S. government course. For example, a tire
graded 150 would wear one and one-half
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 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.
! Avoid wheelspin. This can lead to damage
to the drive train.
The traction grades – from highest to lowest
– are AA, A, B and C. Those grades 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.
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