Mobility
Wheels and tires
DOT Quality Grades
Treadwear
Tire identification marks
Tire size
245/45 R 18 96 Y
Traction AA A B C
Temperature A B C
245: nominal width in mm
45: aspect ratio in %
All passenger car tires must conform to Fed‐
eral Safety Requirements in addition to these
grades.
R: radial tire code
18: rim diameter in inches
96: load rating, not for ZR tires
Y: speed rating, before the R on ZR tires
Treadwear
The treadwear grade is a comparative rating
based on the wear rate of the tire when tested
under controlled conditions on a specified gov‐
ernment test course. For example, a tire
graded 150 would wear one and one-half, 1 g,
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 signifi‐
cantly from the norm due to variations in driv‐
ing habits, service practices and differences in
road characteristics and climate.
Speed letter
T = up to 118 mph, 190 km/h
H = up to 131 mph, 210 km/h
V = up to 150 mph, 240 km/h
W = up to 167 mph, 270 km/h
Y = up to 186 mph, 300 km/h
Tire Identification Number
DOT code: DOT xxxx xxx 1013
xxxx: manufacturer code for the tire brand
xxx: tire size and tire design
1013: tire age
Traction
The 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 concrete. A tire
marked C may have poor traction performance.
Tires with DOT codes meet the guidelines of
the U.S. Department of Transportation.
Tire age
DOT … 1013: the tire was manufactured in the
10th week 2013.
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.
Recommendation
Regardless of wear, replace tires at least every
6 years.
Temperature
The temperature grades are A, the highest, B,
and C, representing the tire's resistance to the
generation of heat and its ability to dissipate
heat when tested under controlled conditions
on a specified indoor laboratory test wheel.
Sustained high temperature can cause the ma‐
terial of the tire to degenerate and reduce tire
life, and excessive temperature can lead to
Uniform Tire Quality Grading
Quality grades can be found where applicable
on the tire sidewall between tread shoulder
and maximum section width.
For example: Treadwear 200; Traction AA;
Temperature A
196
Online Edition for Part no. 01 40 2 911 066 - VI/13