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1.5.9.1. Information on Passenger Vehicle Tires
Please Refer to the Diagram Below
P
The “P” indicates the tire is for passenger vehicles
Next Number
This three-digit number gives the width in millimeters of the tire from sidewall edge to sidewall edge. In gen-
eral, the larger the number, the wider the tire.
Next Number
This two digit number, known as the aspect ratio, gives the tire’s ration of height to width. Numbers of 70 or
lower indicate a short sidewall for improved steering response and better overall handling on dry
pavement.
R
The “R” stands for radial. Radial ply construction of tires has been the industry standard for the past 20 years
Next Number
This two-digit number is the wheel or rim diameter in inches. If you change your wheel size, you will have to
purchase new tires to match the new wheel diameter.
Next Number
This two-or three digit number is the tire’s load index. It is a measurement of how much weight each tire can
support. You may find this information in your owner’s manual.
M + S
The “ M + S” or “M/S” indicates that the tire has some mud and snow capability. Most radial tires have these
markings; hence they have some mud and snow capability.
Speed Rating
The speed rating denotes the speed at which a tire is designed to be driven for extended periods of time. The
ratings range from 99 miles per hour (mph) to 186 mph. These ratings are listed below. Note: You many not
find this information on all tires because it not required by law.