BMW 2009 X6 xDrive50i Owner's Manual

Wheels and tires

254

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 letter

Q = up to 100 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 US Department of Transportation.
DOT code:

Tire age

The manufacturing date of tires is contained in
the tire coding: DOT ... 3008 indicates that the
tire was manufactured in week 30 of 2008.
BMW recommends that you replace all tires
after 6 years at most, even if some tires may last
for 10 years.

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 conform to
Federal Safety Requirements 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 conditions on a specified gov-
ernment 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, how-
ever, and may depart significantly from the
norm due to variations in driving habits, service
practices and differences in road characteris-
tics and climate.

Traction

The traction grades, from highest to lowest,
are AA, A, B, and C.
These grades represent the tire's ability to stop
on wet pavement, as measured under con-
trolled conditions on specified government 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 braking traction

tests, and does not include acceleration, cor-
nering, hydroplaning, or peak traction charac-
teristics.

e.g.
Nominal width in mm
Aspect ratio in

Belted construction – radial
Rim diameter in inches
Carrying capacity ID-code
(not in ZR tires)
Speed code letter
(in ZR tires before the R)

255/55 R

18 109 H

e.g.
Manufacturer code
for tire make
Tire size and tire design
Tire age

DOT xxxx xxx 0806