144 || 145
M
AINTENANCEMAINTENANCE
DOT Tire Quality Grading
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 T
ransportation (D
oT) standards. The following explains these
gradings.
Uniform Tire Quality Grading
Quality grades can be found where applicable on the tire sidewall betwee\
n tread
shoulder and maximum section width.
For example:
Treadwear 200
Traction AA
Temperature A
All passenger car tires must conform to Federal Safety
requirements in addit
ion
to these grades.
Treadwear
The treadwear grade is a comparative rating based on the wear rate of th\
e 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) tim\
es 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, servi\
ce practices,
and differences in road characteristics and climate.
TractionThe traction grades, from highest to lowest, are AA, A, B, and C. Those \
grades
represent the tire’s ability to stop on wet pavement as measured under controlled
conditions on specified government test surfaces of asphalt and concre\
te. 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, hy\
droplaning,
or peak traction characteristics.
Tire Labeling
The tires that came on your vehicle have a number of markings. Those you\
should be aware of are described below.
Here is an example of what each marking means:
P215/55R17 94V
•
P: vehicle type (passenger vehicle)
•
215: tire width in millimeters
•
55: aspect ratio (tire section height as a
percentage of its width)
•
r: tire construction code (radial)
•
17: rim diameter in inches
•
94: load index (code indicating maximum load
tire can carry)
•
v: speed symbol (code indicating maximum speed rating)
Tire Identification Number (TIN)
The tire identification number
(TIN) is a group of numbers
and letters that look like the
example below. TIN is located
on the sidewall of the tire.
Glossary of Tire TerminologyCold Tire Pressure – The tire air pressure when the vehicle has been
parked for at least three hours or driven less than 1 mile (1.6 km).
Load
rating – The maximum load that a tire is rated to carry for a given
inflation pressure.
Maximum Inflation Pressure – The maximum tire air pressure that the\
tire
can hold.
Maximum Load
rating – The load rating for a tire at the maximum
permissible inflation pressure for that tire.
recommended Inflation Pressure – The cold tire inflation pressure \
recommended by the manufacturer
.
Treadwear Indicators (TWI) – The projections within the principal gr\
ooves
designed to give a visual indication of the degrees of wear of the tread\
.
Tire size
Tire
identi cation
number (TIN)
Maximum
tire load
Maximu m
tire pressure
Tire siz e
DOT B97R FW6X 2209
DOT: This indicates that the tire meets all
requirements of the U.S. Department of
Transportation.
B97R: Manufacturer’s identi cation mark
FW6X: Tire type code
22 09: Date of Transportation
Year
Week
