Tuesday

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.

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.

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.

*The Goodyear Tire & Rubber Company does not recommend the use of its products in excess of the legal speed limits

"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
  • 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.

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