Wheel sa nd tires, All about wheels and tires – Mercedes-Benz SLS-Class 2015 Owners Manual User Manual

Page 265

Advertising
background image

Gross axle weight rating: the maximum per-

missible 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 vehi-

cle 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 Stand-

ards

Overview of Tire Quality Grading Stand-

ards

Uniform Tire Quality Grading Standards are

U.S. government specifications. Their pur-

pose is to provide drivers with uniform relia-

ble information on tire performance data. tire

manufacturers have to grade tires using three

performance factors: tread wear :, tire trac-

tion ; and heat resistance =. All tires sold

in North America are provided with the cor-

responding quality class mark on the sidewall

of the tire, even though these regulations do

not apply to Canada.
Quality grades can be found, where applica-

ble, 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, how-

ever, 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, cor-

nering, hydroplaning, or peak traction char-

acteristics.

!

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

263

Wheel

sa

nd

tires

Z

Advertising