The sidewall of a tire contains important information about the tire such as the speed rating, tire grades, tread wear, traction, and temperature. It defines the tire type, width, aspect ratio, construction, wheel diameter, load index, and speed rating. The Uniform Tire Quality Grading system, required by the DOT, grades tires based on tread wear, traction, and temperature resistance to indicate their performance.

1. READING A TYRE
The side of your tyre, known as the sidewall, contains all the information you will
need to know about your tyre. Whether your tyre says "Goodyear" or some other
name, all tyres are required to have this information.
 Speed Rating Chart
 Tyre Grades: Uniform Tyre Quality Grading System or UTQG
 Tread Wear
 Traction
 Temperature

2. Glossary of Terms
Tyre Type defines the proper use of the tyre. “P” means this is a Passenger car tyre.
If the tyre had an “LT” then the tyre would be for a Light Truck.
Tyre Width is the width of the tyre measured in millimetres from sidewall to sidewall.
This tyre is 215 millimetres.
Aspect Ratio is the ratio of the height of the tyre's cross-section to its width. 65
means that the height is equal to 65% of the tyre's width.

3. Construction tells you how the tyre was put together. The "R" stands for radial, which
means that the body ply cords, which are layers of fabric that make up the body of
the tyre, run radially across the tyre from bead to bead. "B" indicates the tyre is of
bias construction, meaning that the body ply cords run diagonally across the tyre
from bead to bead, with the ply layers alternating in direction to reinforce one
another.
Wheel Diameter is the width of the wheel from one end to the other. The diameter of
this wheel is 15 inches.
Load Index is a number that corresponds to the maximum load in kilograms that a
tyre can support when properly inflated. You will also find the maximum load in
pounds and in kilograms moulded elsewhere on the tyre sidewall.
Speed Rating is a number that corresponds to the maximum service speed for a tyre.
"H" means that the tyre has a maximum service speed of 210 km/h. Please note that
this rating relates only to tyre speed capability, and is NOT a recommendation to
exceed legally posted speed limits; always drive within the legal speed limits.
Speed Rating Chart
Many Goodyear tyres are available in speed-rated versions to match the speed
capabilities of the world's fastest cars. Generally, it is recommended that a speed-
rated tyre be replaced with a tyre having an equivalent or greater speed rating.
In situations where tyres having different top speed ratings are mixed on a vehicle,
the maximum speed certification is limited to the top speed certification of the tyre
with the lowest speed rating. Speed ratings do not indicate how well a tyre handles
or corners. They certify the tyre's ability to withstand high speed.

4. "DOT" means the tyre is compliant 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 12
digits.
"UTQG" stands for Uniform Tyre Quality Grading, a quality rating system developed
by the Department of Transportation (DOT).
Tyre Grades: Uniform Tyre Quality Grading
System or UTQG
Except for snow tyres, the DOT requires the manufacturers to grade passenger car
tyres based on three performance factors: tread wear, traction, and temperature
resistance. The UTQG rating of each Goodyear passenger car and light truck tyre is
listed in the Car/Light Truck Tyre Catalogue.
Tread Wear
 More Than 100 - Better

5.  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
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.
Source: http://www.goodyear.com.my/
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