BMW 745i Sedan 2005 - Manual (Page 192)

Whee
ls
and
tires
190
Tire identification marks
Knowledge of the labeling on the side of
the tire makes it easier to identify and
choose the right tires.
Tire size
Speed rating
Q = up to 105 mph/160 km/h
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
Tires with DOT codes meet the guidelines
of the U.S. Department of Transport.
DOT code:
Tire age
The tire's date of manufacture is indicated
on the sidewall:
DOT ... 0904 indicates that the tire was
manufactured in the 9th week of 2004.
BMW recommends that you replace all
tires – including the spare – after a maxi-
mum of 6 years, even though the tires may
have a theoretical service life of up to 10
years.
Uniform Tire Quality Grading
Quality grades can be found where appli-
cable on the tire sidewall between tread
shoulder and maximum section width.
For example:
Treadwear 200 Traction AA
Temperature A
DOT Quality Grades
Treadwear
Traction AA A B C
Temperature A B C
All passenger car tires must conform
to Federal Safety Requirements in
addition to these grades. <
Treadwear
The treadwear grade is a comparative rat-
ing 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
γ, 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.
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 govern-
ment test surfaces of asphalt and concrete.
A tire marked C may have poor traction
performance.
The traction grade assigned to this
tire is based on straight-ahead brak-
ing traction tests, and does not include
acceleration, cornering, hydroplaning, or
peak traction characteristics.
<
e.g.
Nominal width
in mm
Cross-sectional
relationship in
Ξ
Radial tire code
Rim diameter in inches
Load rating,
not for ZR tires
Speed rating,
before R on ZR tires
245/45 R 1 9 104 H
e.g.
Manufacturer code
for tire makes
Tire size and tire design
Tire age
DOT xxxx xxx 0904
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