Tire Specifications. There's a lot of useful information molded into the sidewall of a tire. It shows the name of the tire, its size, whether it is tubeless and more!

Example: P215/65R15 89H

"P" means this is a passenger car tire (as opposed to a tire made for a truck or other vehicle). P-metric is the U.S. version of a metric tire-sizing system.

"215" Section Width: The width of the tire in millimeters from sidewall to sidewall. This measurement varies depending on the width of the rim to which the tire is fitted: larger on a wider rim, smaller on a narrow rim. The number on the side of tire indicates the width measured with the tire fitted to the recommended rim width.

"65" Aspect Ratio: The ratio of height to width; this tire's height is 65% of its width.

"R" Construction: How the plies are constructed in the tire carcass. "R" means radial. "B" in place of the "R" means the tire 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 tire has an industry-standard maximum load of 1,279 lbs. 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 tire has an industry-standard maximum service speed of 130 mph. Tires using an older European system carry the speed rating in the size description: 215/65HR15. Different letters correspond to different maximum service speeds.