7-46
Maintenance
4. Tyre ply composition and
material
The number of layers or plies of rub-
ber-coated fabric that are in the tyre.
Tyre manufacturers also must indi-
cate the materials in the tyre, which
include steel, nylon, polyester, and
others. The letter "R" means radial
ply construction; the letter "D" means
diagonal or bias ply construction;
and the letter "B" means belted-bias
ply construction.
5. Maximum permissible infla-
tion pressure
This number is the greatest amount
of air pressure that should be put in
the tyre. Do not exceed the maximum
permissible inflation pressure. Refer
to the Tyre and Loading Information
label for recommended inflation
pressure.
6. Maximum load rating
This number indicates the maximum
load in kilograms and pounds that
can be carried by the tyre. When
replacing the tyres on the vehicle,
always use a tyre that has the same
load rating as the factory installed
tyre.
7. Uniform tyre quality grading
Quality grades can be found where
applicable on the tyre sidewall
between tread shoulder and maxi-
mum section width.
For example:
TREADWEAR 200
TRACTION AA
TEMPERATURE A
Tread wear
The 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.
7-80
Maintenance
Cleaning the lap/shoulder belt
webbing
Clean the belt webbing with any mild
soap solution recommended for
cleaning upholstery or carpet. Follow
the instructions provided with the
soap. Do not bleach or re-dye the
webbing because this may weaken it.
Cleaning the interior window
glass
If the interior glass surfaces of the
vehicle become fogged (that is, cov-
ered with an oily, greasy or waxy
film), they should be cleaned with
glass cleaner. Follow the directions
on the glass cleaner container.
Do not scrape or scratch the
inside of the rear window. This
may result in damage to the rear
window defroster grid.
CAUTION
