Example- P 235 / 60 / R-16 97S
(P) Passenger (P-Metric) Tire- The United States version of a metric tire sizing system. The letter P as the first character in the tire size means a passenger vehicle tire engineered to standards set by the U.S. Tire and Rim Association.
(235) Tire Width- The three-digit number indicates the tire width in millimeters from sidewall to sidewall.
(60) Aspect Ratio- A two-digit number that indicates the tire height to width measurements. For example, if the tire size aspect ratio is 60, it would mean that the tire's sidewall is 60 percent as high as it is wide.
(R) Construction Code- A letter code is used to indicate the type of ply construction in the tire. A letter R means radial ply construction; the letter D means diagonal or bias ply construction; and the letter B means belted-bias ply construction.
(16) Rim Diameter- Diameter of the wheel in inches.
(97S) Service Description- These characters represent the load index and speed rating of the tire. The load index represents the load carry capacity a tire is certified to carry. The speed rating is the maximum speed a tire is certified to carry a load.