Letter Rating; Speed Rating; Maximum Load Rating- Page 458

Letter Rating

Speed Rating

V

149 mph

W

168

*

 mph

Y

186

*

 mph

*

 For tires with a maximum speed capability over 149 mph, tire manufacturers sometimes use the letters ZR. For

tires with a maximum speed capability over 186 mph, tire manufacturers always use the letters ZR.

M S or M/S: Mud and Snow

AT: All Terrain.
AS: All Season. The “M S” or “M/S” indicates that the tire has some functional use in mud
and snow.

U.S. DOT Tire Identification Number (TIN)

This begins with the letters “DOT” which indicates the tire meets all federal standards. The
next two numbers or letters are the plant code where it was manufactured, and the last four
numbers represent the week and year the tire was manufactured. For example, the numbers
457 means the 45st week of 1997. After 2000 the numbers go to four digits. For example,
the number 2102 means the 21th week of 2002. The other numbers are marketing codes
used at the manufacturer's discretion. This information is used to contact consumers if a tire
defect requires a recall.

Tire Ply Composition and Materials Used

The number of plies indicates the number of layers of rubber-coated fabric in the tire. In
general, the greater the number of plies, the more weight a tire can support. Tire
manufacturers also must indicate the tire materials, which include steel, nylon, polyester,
and other.

Maximum Load Rating

This number indicates the maximum load in kilograms and pounds that can be carried by the
tire.

Maximum Permissible Inflation Pressure

This number is the greatest amount of air pressure that should ever be put in the tire under
normal driving conditions.

Tread Wear, Traction and Temperature Grades

Tread wear:

 The tread wear grade is a comparative rating based on the wear rate of the tire

when tested under controlled conditions on a specified government test course. For
example, 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.

Customer Information and Reporting Safety Defects

Tire Information (U.S.A.)

8-27

MX-5_8JS9-EA-20K_Edition1_old

2020-8-28 13:50:01