BMW z4 2005 Manual Do Utilizador

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Wheels and tires
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Tire coding
Understanding the lettering on the tire sidewall 
makes it easier to identify and choose the cor-
rect tires.
Tire size
e.g.
225/50 R 16 92 V
Nominal width in mm
Cross-sectional
ratio in %
Radial belt construction
Rim diameter in inches
Load index, 
not on ZR tires
Speed code letter, 
in front of the R on ZR tires
Speed code letter
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 Transportation.
DOT code:
e.g.
DOT xxxx xxx 5004
Manufacturer's code 
for tire brand
Tire size and 
tire version
Tire age
Tire age
The date on which the tire was manufactured is 
indicated by the code on the sidewall:
DOT … 5004 indicates that the tire was manu-
factured in week 50 of the year 2004.
BMW recommends the replacement of all tires 
every 6 years at the latest, even if a tire usage 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:
Treadwear 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.
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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 govern-
ment 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 varia-
tions in driving habits, service practices and dif-
ferences 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 government test sur-
faces 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.
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Online Edition for Part-No. 01 41 0 158 704 - © 10/04 BMW AG