User Guide

Document Control No. C90.CD.QA.018.H
Effective 6-December-2021
Load Index Number, a numeric code which indicates the maximum load carrying capacity of a
tire at the maximum cold inflation pressure.
Speed Symbol, an alphabetical code which indicates the maximum speed at which the tire can
carry a load corresponding to its Load Index when properly inflated. These two items together
are known as the “Service Description”.
Speed Symbol Chart
SPEED SYMBOLS Q R S T U H V W Y (Y)
MPH 99 106 112 118 124 130 149 168 186 >186
*For tires having a maximum speed capability above 149 mph, a “ZR” may appear in the size
designation; above 186 mph, a “ZR” must appear in the size designation, and a Service
Description, including the “Y” speed symbol, must be included in brackets.
Other Markings:
P - As part of the tire size designation (e.g., P205/65R15), is used to indicate tires intended for
service on passenger cars.
LT - As part of the tire size designation (e.g. LT235/75R15), is used to indicate the tires are
intended for service on light truck vehicles.
XL - As part of the size designation (e.g. P235/75R16 XL), is used to indicate the tire can carry
more load as the maximum inflation pressure and load are greater than a standard load version.
(Also could be called REINFORCED).
HL - As part of the tire size designation (e.g., HL215/55R17), is used to indicate tires that
provide an increased load capacity in comparison with extra load tires at the same reference
inflation pressure.
M&S, M+S, M/S - Letters used to indicate a tire suitable for Mud and Snow and/or All Season
usage.
- 3 peak mountain snowflake pictograph used to indicate a tire suitable for use in severe
snow conditions.
2. Tire Categories:
ALL SEASON TIRES: Tires that are designed to perform in a variety of road conditions in All
Seasons of the year. An All Season tire will carry "M+S", "M&S", or "M/S" designation on the
sidewall.
SUMMER TIRES: Summer tires offer superior handling, grip and cornering ability compared to
standard tires under certain conditions.
WINTER TIRES (Snow Tires): A winter tire is a tire with a tread design and compound made
specifically for snow and ice conditions and is identified by a 3 peak mountain snowflake
pictograph on the sidewalls and must meet specific snow performance test requirements.
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