Tire Safety Information
manual. If not, contact a local tire dealer. Note: You may not find this information
on all tires because it is not required by law.
M+S
The "M+S" or "M/S" indicates that the tire has some mud and snow capability. Most
radial tires have these markings; hence, they have some mud and snow capability.
Speed Rating
The speed rating denotes the speed at which a tire is designed to be driven for
extended periods of time. The ratings range from 99 miles per hour (mph) to 186
mph. These ratings are listed below. Note: You may not find this information on all
tires because it is not required by law.
Letter Rating Speed Rating
Q 99 mph
R 106 mph
S 112 mph
T 118 mph
U 124 mph
H 130 mph
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 those with a maximum speed capability over
186 mph, tire manufacturers always use the letters ZR.
U.S. DOT Tire Identification Number
This begins with the letters "DOT" and indicates that 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
built. For example, the numbers 3197 means the 31st week of 1997. 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 materials in the tire, which include steel,
nylon, polyester, and others.
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.
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