Department Of Transportation Uniform Tire Quality Grades; Treadwear; Traction Grades - Fiat 500X 2018 Owner's Manual

The suggested Four Wheel Drive (4WD) Tire rotation
method is the "rearward cross" shown in the following
diagram.
Four Wheel Drive (4WD) Tire Rotation
CAUTION!
Proper operation of four-wheel drive vehicles depends
on tires of equal size, type and circumference on each
wheel. Any difference in tire size can cause damage to
the power transfer unit. Tire rotation schedule should
be followed to balance tire wear.
SERVICING AND MAINTENANCE 373
DEPARTMENT OF TRANSPORTATION UNIFORM
TIRE QUALITY GRADES
The following tire grading categories were established
by the National Highway Traffic Safety Administration.
The specific grade rating assigned by the tire's manu-
facturer in each category is shown on the sidewall of the
tires on your vehicle.
All passenger vehicle tires must conform to Federal
safety requirements in addition to these grades.

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 charac-
teristics 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
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