Passenger Tire Sidewall Example P225/60R16 92V
"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.
"225" 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, or design, rim width.
"60" Aspect Ratio: The ratio of height to width; this tire's sidewall height is 60% 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 (or bias) construction.
"16" Rim Diameter: The diameter of the wheel (or rim) in inches.
"98" Load Index: Load Index is a rating which reflects the load capacity of the tire. This tire has a load capacity of 1,653 lbs.
For a more complete listing see the chart under Load Index and Speed Rating.
"V" Speed Rating: This tire has an industry-standard maximum service speed of 149 mph. Tires using an older European system carry the speed rating in the size description: 225/60VR16. Different letters correspond to different maximum service speeds.
The letters "DOT" certify compliance with all applicable safety standards established by the U.S. Department of Transportation (DOT). Adjacent to this is a tire's identification or serial number; a combination of numbers and letters with up to 12 digits.
The sidewall also shows the type of cord and number of plies in the sidewall and under the tread.