Tire condition – BMW X3 2.5i SAV 2005 User Manual
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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 conditions
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 temperature can lead to
sudden tire failure. The grade C corresponds to
a level of performance which all passenger car
tires must meet under the Federal Motor Vehi-
cle Safety Standard No. 109. Grades B and A
represent higher levels of performance on the
laboratory test wheel than the minimum
required by law.
The temperature grade for this tire is
established for a tire that is properly
inflated and not overloaded. Excessive speed,
underinflation, or excessive loading, either sep-
arately or in combination, can cause heat
buildup and possible tire failure.
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M+S
Winter and all-season tires.
These have better winter properties than sum-
mer tires.
Tire condition
Inspect your tires frequently for tread wear,
signs of damage and for foreign objects lodged
in the tread. Check the tread pattern depth.
Tire tread
The tread depth should not drop below 0.12 in/
3 mm, although, for example, European legisla-
tion only specifies a minimum tread depth of
0.063 in/1.6 mm.
At tread depths below 0.12 in/3 mm, there is an
increased risk of high-speed hydroplaning,
even when only small amounts of water are
present on the road surface. As winter tires dis-
play a noticeable loss in their ability to cope with
cold-weather driving conditions once the tread
wears to below 0.16 in/4 mm, to ensure contin-
ued safety you should always have such tires
replaced.
Wear indicators at the tread-groove base, refer
to arrow, are distributed over the tire's circum-
ference and are marked on the side of the tire
with TWI – Tread Wear Indicator. At a tread
depth of 0.063 in/1.6 mm these indicators, sig-
nal that the tires have reached the legally per-
missible wear limit.
Wheel/tire damage
Due to low-profile tires, please note that
wheels, tires and suspension parts are
more susceptible to road hazard and conse-
quential damages.
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Unusual vibrations encountered during normal
vehicle operation can indicate tire failure or
some other vehicle defect. This can, for exam-
ple, be caused by driving over curbs. These
kinds of problems may also be signaled by other
changes in vehicle response, such as a strong
tendency to pull to the left or right.
In these cases reduce speed immedi-
ately. Drive carefully to the next BMW
Sports Activity Vehicle Center or tire dealer, or
have the vehicle towed to one of these locations
if necessary.
Tire damage, extending to sudden and com-
plete loss of pressure in extreme cases, can
pose a potentially lethal safety hazard for the
vehicle's occupants and other road users
alike.
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