Your tires can't talk, but they have a lot to say. Not all tires are created equal, and most of the details that make the difference between a Bridgestone Blizzak and a Pirelli P Zero are
It tells us the size of the wheel that the tire is intended to fit. A size P215/65 R15 tire is made for a wheel with a 15" diameter. Load Index Indicates the maximum load that the tire can support when properly inflated. You'll also find the maximum load on the tire sidewall, in both pounds and kilograms. Learn more about tire load index.
A typical tire size might read: P 205/65 R 15 92 H Here's what that means. P — This denotes a Passenger or P-metric tire built to U.S. standards. Here are other possible prefixes: LT is for a light truck. ST is for a special trailer. T is for temporary, usually indicating a spare tire. European-standard tires won't have a prefix letter at all.
Tire Size Meaning. There are two ways that tire manufacturers display tire size, inches and metric. To find the tire size meaning in inches is very straight forward. Example A : 33X12.50R15. The first number is your overall diameter of the tire. In this example the tire diameter or "height" is 33 inches tall.
The numbers and letters on a tire mean tire type, width, height to width ratio, construction type, diameter, load index, and speed rating. Some tires also list the severe weather rating. . 607 415 37 689 641 370 231 322

what do tire sizes mean