Maintenance42
7Tread wearThe tread wear grade is a compara-
tive rating based on the wear rate of
the tyre when tested under controlled
conditions on a specified govern-
ment test course. For example, a tyre
graded 150 would wear one-and-a-
half times (1½) as well on the gov-
ernment course as a tyre graded
100.
The relative performance of tyres
depends upon the actual conditions
of their use, however, and may
depart significantly from the norm
because of variations in driving
habits, service practices and differ-
ences in road characteristics and cli-
mate.
These grades are molded on the
side-walls of passenger vehicle
tyres. The tyres available as standard
or optional equipment on your vehi-
cles may vary with respect to grade.
Traction - AA, A, B & C The traction grades, from highest to
lowest, are AA, A, B and C. Those
grades represent the tyres ability to
stop on wet pavement as measured
under controlled conditions on spec-
ified government test surfaces of
asphalt and concrete. A tyre marked
C may have poor traction perform-
ance.
Temperature -A, B & C The temperature grades are A (the
highest), B and C representing the
tyre’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 tempera-
ture can cause the material of the
tyre to degenerate and reduce tyre
life, and excessive temperature can
lead to sudden tyre failure. Grades B
and A represent higher levels of per-
formance on the laboratory test
wheel than the minimum required by
the law.
WARNING
The traction grade assigned to
this tyre is based on straight-
ahead braking traction tests,
and does not include accelera-
tion, cornering, hydroplaning,
or peak traction characteristics.
WARNING - Tyre
temperature
The temperature grade for this
tyre is established for a tyre that
is properly inflated and not
overloaded. Excessive speed,
underinflation, or excessive
loading, either separately or in
combination, can cause heat
build-up and possible sudden
tyre failure. This can cause loss
of vehicle control and serious
injury or death.
EL(FL) UK 7.QXP 3/4/2015 9:05 PM Page 42
