RAM 1500 Owner's Manual page 734

732 IF YOU NEED CONSUMER ASSISTANCE
Treadwear
The Treadwear grade is a comparative rating, based on
the wear rate of the tire when tested under controlled
conditions on a specified government test course. For
example, a tire graded 150 would wear one and one-half
times as well on the government course as a tire
graded 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
The Traction grades, from highest to lowest, are AA, A, B,
and C. These grades represent the tire's ability to stop on wet
pavement, as measured under controlled conditions on
specified government test surfaces of asphalt and concrete.
A tire marked C may have poor traction performance.
WARNING!
The traction grade assigned to this tire is based on
straight-ahead braking traction tests, and does not
include acceleration, cornering, hydroplaning, or
peak traction characteristics.