BMW 325iT Sports Wagon 2004 - Manual (Page 125)

125
Do not drive on a deflated – flat –
tire unless your vehicle is
equipped with Run Flat tires. A flat tire
greatly impairs steering and braking
response, and can lead to complete
loss of control over the vehicle.
Avoid overloading the vehicle so that
the permitted load on the tires is not
exceeded. Overloading can lead to
overheating and internal tire damage.
The ultimate result can assume the
form of a sudden air loss.
Unusual vibrations encountered during
normal vehicle operation can indicate a
damaged tire or some other vehicle
malfunction. This type of problem can
be caused by contact with curbs, etc.
This is also true for irregularities in the
vehicle's handling characteristics, such
as a pronounced tendency to pull to the
left or right. Should this occur, respond
by immediately reducing your speed.
Proceed carefully to the nearest BMW
center 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.
Comply with the specified tire inflation
pressures — and be sure to have the
wheel and tire assembly balanced
every time you change a tire or wheel.
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 performance.
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.
Tire condition
Overview
Controls
Maintenance
Repairs
Data
Index
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