Wheels and tires, All about wheels and tires – Mercedes-Benz SLS-Class 2014 Owners Manual User Manual

Page 263

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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.

Example:

R

Treadwear grade: 200

R

Traction grade: AA

R

Temperature grade: A

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.

All about wheels and tires

261

Wheels

and

tires

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