TIRE CARE
Glossary of Tire Terminology
*
Tire label:
A label showing the
original equipment tire sizes,
recommended inflation pressure
and the maximum weight the
vehicle can carry.
*
Tire Identification Number:
A
number on the sidewall of each
tire providing information about
the tire brand and manufacturing
plant, tire size and date of
manufacture. Also referred to as
DOT code.
*
Inflation pressure:
A measure
of the amount of air in a tire.
*
Standard load:
A class of
P-metric or Metric tires designed
to carry a maximum load at set
pressure. For example: For
P-metric tires 35 psi (2.4 bar) or
36 (2.5 bar) depending on tire size
and for Metric tires 36 psi (2.5
bar). Increasing the inflation
pressure beyond this pressure will
not increase the tire’s load
carrying capability.
*
Extra load:
A class of P-metric
or Metric tires designed to carry a
heavier maximum load at 42 psi
(2.9 bar). Increasing the inflation
pressure beyond this pressure will
not increase the tire’s load
carrying capability.
*
kPa:
Kilopascal, a metric unit of
air pressure.
*
PSI:
Pounds per square inch, a
standard unit of air pressure.
*
Cold tire pressure:
The tire
pressure when the vehicle has
been stationary and out of direct
sunlight for an hour or more and
prior to the vehicle being driven for
1 mile (1.6 kilometers).
*
Recommended inflation
pressure:
The cold inflation
pressure is found on the Safety
Compliance Certification Label,
located in the driver's door jam.
*
Bead area of the tire:
Area of
the tire next to the rim.
*
Sidewall of the tire:
Area
between the bead area and the
tread.
*
Tread area of the tire:
Area of
the perimeter of the tire that
contacts the road when mounted
on the vehicle.
*
Rim:
The metal support (wheel)
for a tire or a tire and tube
assembly upon which the tire
beads are seated.
Information Contained on the
Tire Sidewall
Both United States and Canada
Federal regulations require tire
manufacturers to place
standardized information on the
sidewall of all tires. This
information identifies and
232
F650750 (TBC), enUSA, First Printing
Wheels and Tires
