Tire Sidewalls reveal 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 or tube type, the tire grade, speed rating, maximum load, maximum inflation, an important safety warning,etc.

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.

“LT” would signify a light truck tire.

"215" is the 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" represents the aspect ratio. This is the ratio of height to width. This tire's height is 65% of its width. "R" stands for 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" is the rim diameter, which is the diameter of the wheel in inches.

"89" indicates the load index.