There's a lot of useful information molded
into the sidewall of a Tyre. It shows the name of the
Tyre, its size, whether it is tubeless or tube type,
the Tyre grade, speed rating, the maximum load, maximum
inflation, an important safety warning and more. Click
an area within the Tyre graphic to learn about the individual
fields of information. (Following the graphic is a scrollable
summary of this information.)
Passenger Tyre Sidewall
Information
Example: P215/65R15 89H
"P" means this is a passenger car Tyre (as
opposed to a Tyre made for a truck or other vehicle).
P-metric is the U.S. version of a metric Tyre-sizing
system.
"215" Section Width: The width of the Tyre
in millimeters from sidewall to sidewall. This measurement
varies depending on the width of the rim to which the
Tyre is fitted: larger on a wider rim, smaller on a
narrow rim. The number on the side of Tyre indicates
the width measured with the Tyre fitted to the recommended
rim width.
"65" Aspect Ratio: The ratio of height to
width; this Tyre's height is 65% of its width.
“R" Construction: How the plies are constructed
in the Tyre carcass.
"R" means radial.
"B" in place of the "R" means the
Tyre is belted bias construction.
"D" in place of the "R" means diagonal
bias construction.
15" Rim Diameter: The diameter of the wheel in
inches.
"89" Load Index: This Tyre has an industry-standard
maximum load of 580 kilogram. Different numbers correspond
to different maximum loads. The maximum load is shown
in lbs. (pounds) and in kg (kilograms), and maximum
pressure in PSI (pounds per square inch) and in kPa
(kilopascals). Kilograms and kilopascals are metric
units of measurement.
"H"Speed Rating: This Tyre has an industry-standard
maximum service speed of 210 km per hour. Tyres using
an older European system carry the speed rating in the
size description: 215/65HR15. Different letters correspond
to different maximum service speeds.
The letters "DOT" certify compliance with
all applicable safety standards established by the U.S.
Department of Transportation (DOT). Adjacent to this
is a Tyre identification or serial number; a combination
of numbers and letters with up to 11 digits.
The sidewall also shows the type of cord and number
of plies in the sidewall and under the tread.
Tyre Grades: Uniform Tyre Quality Grading System
or UTQG
Except for snow Tyres, the DOT requires Tyre
manufacturers to grade passenger car Tyres based on
three performance factors: tread wear, traction and
temperature resistance.
Tread Wear

More Than 100 - Better

100 - Baseline

Less Than 100 - Poorer
The tread wear grade is a comparative rating based on
the wear rate of the Tyre when tested under controlled
conditions on a specified government test track. A Tyre
graded 200 would wear twice as long on the government
test track as one graded 100. Your actual Tyre mileage
depends upon the conditions of their use and may vary
due to driving habits, service practices, differences
in road characteristics and climate. Note: Tread wear
grades are valid only for comparisons within a manufacturer's
product line. They are not valid for comparisons between
manufacturers.
Traction

A - Best

B - Intermediate

C - Acceptable
Traction grades represent the Tyre 's ability to stop
on wet pavement as measured under controlled conditions
on specified government test surfaces of asphalt and
concrete. The Traction grade is based upon "straight
ahead" braking tests; it does not indicate cornering
ability
Temperature

A - Best.

B - Intermediate

C - Acceptable
Load Index and Speed Rating
The temperature grades represent the Tyre's resistance
to the generation of heat when tested under controlled
conditions on a specified indoor laboratory test wheel.
Sustained high temperatures can cause the materials
of the Tyre to degenerate and thus reduce Tyre life.
Excessive temperatures can lead to Tyre failure. Federal
law requires that all Tyres meet at least the minimal
requirements of Grade C.
The speed rating is the maximum service speed of a passenger
car Tyre. Light truck Tyres are not speed rated. Here
is a list of rating indicators and their mile-per-hour
equivalents. This rating system applies to all Tyre
makers.
| |
|
| Q |
99
mph |
| S |
112
mph |
| T |
118
mph |
| U |
124
mph |
| H |
130
mph |
| V |
Above
130 mph (without service description) |
| V |
149
mph (with service description) |
| Z |
Above
149 mph |
Light Truck Sidewall Information
"LT" stands for Light Truck
"LT235/85R16" is the size designation for
a metric light truck Tyre
"LOAD RANGE D" identifies the load and inflation
limits
"RADIAL" indicates that the Tyre has a radial
construction
"MAX. LOAD SINGLE 2623 lbs. AT 65 psi COLD"
indicates the maximum load rating of the Tyre and
corresponding minimum cold inflation pressure when
used in a dual configuration. The other markings on
the sidewall have the same meaning as described for
the passenger car Tyre.

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