Tire condition – BMW 2004 Mini Convertible Cooper User Manual

Page 102

100

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.

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.

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

101

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

The tread depth should not fall below
ε in / 3 mm.
Below

ε in / 3 mm tread depth, there is a

very high danger of hydroplaning at higher
speeds even if there is only a small amount
of water on the road.
Below a tread depth of

in / 4 mm, win-

ter tires display a perceptible decrease in
their ability to cope with winter driving
conditions, and should be replaced in the
interest of safety.