BMW 2006 bmw 325i - Manual (Page 118)

118 Tire code
Knowing the tire code on the tire side-
wall makes it easier to correctly choose
and identify your tires.
Tire size
E.g. 205/60 R 15 91 W
205 = Nominal width in mm
60 = Cross-sectional ratio in %
R = Radial belt construction
15 = Rim diameter in inches
91 = Load index, not on ZR tires
W = Speed rating, in front of the R on
ZR tires
Speed rating
Q = up to 100 mph (160 km/h)
T = up to 118 mph (190 km/h)
H = up to 130 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
Tires with DOT codes comply with the
guidelines of the U.S. Department of
Transportation.
DOT code:
E.g. DOT xxxx xxx 1004
xxxx = Manufacturer's code for tire
brand
xxx = Tire size and tire version
1004 = Tire age
Tire age
The date on which the tire was manu-
factured is indicated by the code on the
sidewall:
DOT … 1004 indicates that the tire was
manufactured in week 10 of the year
2004.
BMW recommends the replacement of
all tires when they are no more than
6 years old, even if a tire life of 10 years
is possible.
Uniform Tire Quality Grading
Quality grades can be found where
applicable on the tire sidewall between
tread shoulder and maximum section
width. For example:
Tread wear 200 Traction AA
Temperature A
DOT quality grades
Tread wear
Traction AA A B C
Temperature A B C
All passenger car tires must con-
form to Federal Safety Require-
ments in addition to these grades. <
Tread wear
The tread wear grade is a comparative
rating based on the wear rate of the tire
when tested under controlled condi-
tions 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 condi-
tions of their use, however, and may
depart significantly from the norm due
to variations in driving habits, service
practices and differences in road char-
acteristics and climate.
Traction
The traction grades, from highest to
lowest, are AA, A, B, and C.
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