Reading a Tyre Sidewall
Everything You Need To Know — Your Sidewall Has It
The side of your tyre — known as the sidewall — contains all of the information you need to know about your tyre. Whether your tyre comes from Goodyear or some other manufacturer, all tyres are required to show this information.
Tyre Type defines the proper use of the tyre. For example, the “P” on the tyre shown here means that this is a passenger car tyre. If the tyre had an “LT” designation, the tyre would be for a light truck.
Tyre Width is the width of the tyre measured in millimeters from sidewall to sidewall. This tyre width is 215 millimeters.
Aspect Ratio is the ratio of the height of the tyre's cross-section to its width. On our example, 65 means that the height is equal to 65% of the tyre's width.
Construction tells you how the layers of the tyre were put together. The “R” stands for Radial which means the layers run radially across the tyre. A “B” stands for bias construction which means that the layers run diagonally.
Wheel Diameter is the width of the wheel from one end to the other. The diameter of this wheel is 15 inches.
Load Index indicates the maximum load in pounds that the tyre can support when properly inflated. You'll also find the maximum load elsewhere on the tyre sidewall, both in pounds and kilograms.
Speed Rating tells you the maximum service speed for a tyre. “H” means that the tyre has a maximum service speed of 130 mph. This rating relates only to tyre speed capability and is NOT a recommendation to exceed legally posted speed limits.
DOT means that the tyre complies with all applicable safety standards established by the U.S. Department of Transportation (DOT). Next to this is a tyre identification or serial number — a combination of numbers and letters up to 12 digits.
UTQG stands for Uniform Tyre Quality Grading, a rating system developed by DOT. For more information on UTQG, continue here.