How To Read A tyre's Sidewall
Passenger Example: P215/65R15 89H
The "P" stands for "P-Metric" or "Passenger". This generally means this is a North American tire, as European Tyres typically don't have the prefix "P".
The first number (215 in this example) is a three-digit number which refers to the section width of the tire at it's widest point, in millimeters.
The second number (65 in this example) refers to the aspect ratio, which is the relationship between the tyre's height and it's width. In this example, the sidewall's height is about 65% of the tyre's width.
The letter following the aspect ratio is usually an "R" standing for radial construction. Other types are "B" for belted construction and "D" for diagonal construction.
The next number indicates the diameter of the wheel rim on which the tire will fit (15 inches, in this example).
The "89" in this example is the load index. The load index indicates the maximum weight that each tire is able to bear. See the chart below for further information.
The "H" is the speed rating. The speed rating of any tire is an indication of the top safe speed for each tire. A higher rated tire will generally give better traction and improved steering at lower speeds.
Light Truck Example: LT235/85R16M+S
In this example the prefix is "LT" which denotes Light Truck.
The "M+S" suffix indicates this tire is used in mud and snow applications.
