Tire coding, Tire condition, Tire condition 113 – Mini 2008 Cooper Convertible User Manual
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113
TIRE CODING
TIRE CONDITION
Traction
The traction grades, from highest to low-
est, 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 govern-
ment test surfaces of asphalt and concrete.
A tire marked C may have poor traction per-
formance.
The traction grade assigned to this
tire is based on straight-ahead brak-
ing traction tests, and does not include
acceleration, cornering, hydroplaning, or
peak traction characteristics.
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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 con-
trolled conditions on a specified indoor lab-
oratory 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 Vehicle Safety
Standard No. 109. Grades B and A represent
higher levels of performance on the labora-
tory 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 separately or in combination, can
cause heat buildup and possible tire fail-
ure.
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RSC: Run-Flat Tires
You will recognize Run-Flat Tires by a circu-
lar symbol containing the letters RSC on
the side of the tire, refer to page
M+S
Winter and all-season tires.
These have better winter performance
properties than summer tires.
Inspect your tires frequently for tread wear,
signs of damage and for foreign objects
lodged in the tread. Check the tread depth.
Tire tread
Tread depth should not be allowed to go
below 1/8 in/3 mm even though in Europe,
for example, the legally specified minimum
tread depth is only 1/16 in/1.6 mm.
Below 1/8 in/3 mm tread depth, there is a
very high danger of hydroplaning at higher
speeds, even with only small amounts of
water on the road.
At tread depths below approx. 1/6 in/
4 mm, the ability of winter tires to cope
with winter driving conditions decreases
perceptibly. For safety reasons, new tires
should be mounted.
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