Understanding Tire Markings
Laws require tire manufacturers to place standardized information on the sidewall of all tires.
This information identifies and describes the fundamental characteristics of the tire.
1
Tire category. P indicates that the tire is for passenger vehicles.
2
Tire width. This 3-digit number is the width (in millimeters) of the tire from sidewall edge
to sidewall edge.
3
Aspect ratio. This 2-digit number is the sidewall height as a percentage of the tread
width. So, if the tread width is 205 mm, and the aspect ratio is 50, the sidewall height is
102 mm.
4
Tire construction. R indicates that the tire is of Radial ply construction.
5
Wheel diameter. This 2-digit number is the diameter of the wheel rim in inches.
6
Load index. This 2 or 3-digit number is the weight each tire can support. This number is
not always shown.
Wheels and Tires
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MODEL S OWNER'S MANUAL