Checking and Maintaining Tires
Tire and Loading Information Label
260Maintenance
Tire and Loading Information LabelThe label attached to the driver’s doorjamb provides necessary tire and
loading information.
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3
Label
Example
Tire SizeFollowing is an example of tire size with
an explanation of what each component
means.
P225/50 R17 93V
P: Vehicle type (P indicates passenger
vehicle).
225: Tire width in millimeters.
50: Aspect ratio (the tire’s section height
as a percentage of its width).
R: Tire construction code (R indicates
radial).
17: Rim diameter in inches.
93: Load index (a numerical code
associated with the maximum load the
tire can carry).
V: Speed symbol (an alphabetical code
indicating the maximum speed rating).
Tire Labeling
The tires that came on your vehicle have
a number of markings. Those you should
be aware of are described below.
Tire Size
Whenever tires are replaced, they should be replaced with tires of the
same size.
Tire and Loading Information LabelThe tire and loading information label
attached to the driver’s doorjamb
contains:1 The number of people your vehicle can
carry.2 The total weight your vehicle can carry.
Do not exceed this weight.3 The original tire sizes for front, rear and
spare.4 The proper cold tire pressure for front,
rear and spare.
Checking and Maintaining Tires
DOT Tire Quality Grading (U.S. Vehicles)
262Maintenance
DOT Tire Quality Grading (U.S. Vehicles)The tires on your vehicle meet all U.S. Federal Safety Requirements. All
tires are also graded for treadwear, traction, and temperature performance
according to Department of Transportation (DOT) standards. The following
explains these gradings.
Uniform Tire Quality Grading
Quality grades can be found where applicable on the tire sidewall between
tread shoulder and maximum section width.
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
(1 1/2) 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.
Uniform Tire Quality GradingFor example:
Treadwear 200
Traction AA
Temperature A
All passenger car tires must conform to
Federal Safety Requirements in addition
to these grades.
