BMW 325XI Manual Do Utilizador

Página de 166
118
ceed carefully to the nearest BMW cen-
ter or professional tire center, or have 
the vehicle towed in to have it, its 
wheels or its tires inspected.
Tire damage up to and including sud-
den and complete air loss can endan-
ger the lives of both the vehicle occu-
pants and other road users.
<
Tire replacement
To maintain good handling and vehicle 
response, use only tires of a single 
tread configuration from a single manu-
facturer.
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.
Those grades represent the tire's ability 
to stop on wet pavement as measured 
under controlled conditions on speci-
fied government test surfaces of 
asphalt and concrete. A tire marked C 
may have poor traction.
The traction grade assigned to 
this tire is based on straight-
ahead braking traction tests, and does 
not include acceleration, cornering, 
hydroplaning, or peak traction charac-
teristics.
<
Temperature
The temperature grades are A – the 
highest – B, and C, representing the 
tire's resistance to the generation of 
heat and its ability to dissipate heat 
when tested under controlled condi-
tions on a specified indoor laboratory 
test wheel.
Sustained high temperature can cause 
the material of the tire to degenerate 
and reduce tire life, and excessive tem-
perature can lead to sudden tire failure. 
The grade C corresponds to a level of 
performance which all passenger car 
Tire condition
Online Edition for Part-No. 01 41 0 156 804 - © 09/02 BMW AG