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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
LETTER DESIGNATION
SPEED RATING
Q 99
MPH
R 106
MPH
S 112
MPH
T 118
MPH
U 124
MPH
H 130
MPH
V 149
MPH
W 169*
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.
Additional Information on Light Truck Tires
Tires for light trucks have other markings besides those found on the sidewalls of passenger
tires:
LT -
The "LT" indicates the tire is for light trucks or trailers.
ST -
An "ST" is an indication the tire is for trailer use only.
Max. Load Dual kg (lbs) at kPa (psi) Cold -
This information indicates the maximum load and
tire pressure when the tire is used as a dual; that is, when four tires are put on each rear axle (a
total of six or more tires on the vehicle).
Max. Load Single kg (lbs) at kPa (psi) Cold -
This information indicates the maximum load
and tire pressure when the tire is used as a single.
Summary of Contents for T2801
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