Hyundai i20 Owner's Manual page 399

Maintenance
4. Tire ply composition and material
The number of layers or plies of
rubber-coated fabric in the tire. Tire
manufacturers also must indicate the
materials in the tire, 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 inflation
pressure
This number is the greatest amount
of air pressure that should be put in
the tire. Do not exceed the maximum
permissible inflation pressure. Refer to
the Tire 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 tire. When replacing
the tires on the vehicle, always use a
tire that has the same load rating as the
factory installed tire.
10-60
7. Uniform tire quality grading
Quality grades can be found where
applicable on the tire sidewall between
tread shoulder and maximum chapter
width.
For example:
TREAD wear 200
TRACTION AA
TEMPERATURE A
Tread wear
The tread wear grade is a comparative
rating based on the wear rate of the tire
when tested under controlled conditions
on a specified government test course.
For example, a tire graded 150 would
wear one-and-a-half times (1½) as well
on the government course as a tire
graded 100.
The relative performance of tires
depends upon the actual conditions
of their use, however, and may depart
significantly from the norm due to
variations in driving habits, service
practices and differences in road
characteristics and climate.
These grades are molded on the side-
walls of passenger vehicle tires. The
tires available as standard or optional
equipment on your vehicle may vary
with respect to grade.