BMW 745i Sedan 2004 - Manual (Page 192)

Wheels 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 ... 3603 indicates that the tire was
manufactured in the 36th week of 2003.
Regardless of mileage or wear, BMW rec-
ommends that you replace all tires – includ-
ing the spare – after a maximum of 6 years,
even though the tires may have a theoreti-
cal 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 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 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
Aspect ratio in X
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 3603
Online Edition for Part No. 01 41 0 157 670 - © 08/03 BMW AG