User Guide

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Always consult the tire manufacturer for the maximum speed of Unlimited Z or (Y)
tires. Speed rating is identied as a part of the tire’s sizing or service description.
Exceeding the lawful speed limit is neither recommended nor endorsed.
In the latest attempt to standardize tire designations, all ratings except Unlimited
Z incorporate the speed symbol and load index as the tire’s service description.
For Example:
205/60R15 91V
205 = Section Width in Millimeters
60 = Aspect Ratio
R = Radial Construction
15 = Rim Diameter in Inches
91V = Service Description (Load Index and Speed Rating)
“Z” Rated Tires
When “Z” appears in the size description with the service description, the
maximum speed is indicated by the service description.
Examples:
Tire Designation Maximum Speed
P275/40ZR17 Above 240 km/hr (149 mph)*
P275/40R17 93Y 300 km/hr (186 mph)
P275/40ZR17 93Y 300 km/hr (186 mph)
P275/40ZR17 (93Y) Above 300 km/hr (186 mph)*
*Consult Tire Manufacturer
For tires having a maximum speed capability above 240 km/hr (149 mph), a “Z”
may appear in the size designation.
For tires having a maximum speed capability above 300 km/hr (186 mph), a “Z”
must appear in the size designation and the service description must include Y
in parenthesis. Example: 275/40ZR18 (99Y). Consult the tire manufacturer for
maximum speed when there is no service description.
Consult your Michelin tire retailer for maximum speed capabilities. Although a
tire may be speed-rated, no vehicle should be operated in an unsafe or unlawful
manner. Speed ratings are based on laboratory tests that relate to performance
on the road, but are not applicable if tires are underinated, overloaded, worn
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