Federal Motor Vehicle Safety
Standard No. 139. Grades B and A
represent higher levels of
performance on the laboratory
test wheel than the minimum
required by law.
Glossary of Tire Terminology
•
Tire label:
A label showing the
OE (Original Equipment) tire
sizes, recommended inflation
pressure and the maximum
weight the vehicle can carry.
•
Tire Identification Number
(TIN):
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) and for Metric
tires 36 psi (2.5 bar). Increasing
the inflation pressure beyond
this pressure will not increase
the tire 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.
•
bar
Metric unit of atmospheric
pressure.
•
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 mi (1.6 km).
•
Recommended inflation
pressure:
The cold inflation
pressure found on the Safety
Compliance Certification Label
(affixed to either the door hinge
pillar, door-latch post, or the
door edge that meets the
door-latch post, next to the
driver seating position) or Tire
Label located on the B-Pillar or
the edge of the driver door.
•
B-pillar:
The structural
member at the side of the
vehicle behind the front door.
•
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.
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2018 Transit (TTH) Canada/United States of America, JK3J 19A321 AA enUSA, Edition date: 201705, First Printing
Wheels and Tires
