2021 RAM 2500 Owner’s Manual — DEPARTMENT OF TRANSPORTATION UNIFORM TIRE QUALITY GRADES

uses unique sensors in the inner rear wheels

to help identify them from the outer rear wheels, because of this, the inner and outer wheel locations can’t be switched.

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All passenger vehicle tires must conform to Federal safety requirements in addition to these grades.

TREADWEAR

100. The relative performance of tires depends upon the actual conditions of their use, however, and may depart significantly from the norm due to variations in driving habits, service practices, and differences in road characteristics and climate.

TRACTION GRADES

controlled conditions on specified government test surfaces of asphalt and concrete. A tire marked C may have poor traction performance.

TEMPERATURE GRADES

Sustained high temperature can cause the material of the tire to degenerate and reduce tire life, and excessive temperature can lead to sudden tire failure. The grade C corresponds to a

level of performance, which all passenger vehicle tires must meet under the Federal Motor Vehicle Safety Standard No. 109. Grades B and A represent higher levels of performance on the laboratory test wheel, than the minimum required by law.