Recommended inflation pressure: the
inflation pressure for optimum tire perfor-
mance.
Intended outboard sidewall:
• The sidewall that contains a whitewall,
bears white lettering or bears manufac-
turer, brand, and/or model name molding
that is higher or deeper than the same
molding on the other sidewall of the tire,
or
• The outward facing sidewall of an asym-
metrical tire that has a particular side
that must always face outward when
mounted on a vehicle.
Passenger car tire: a tire intended for use
on passenger cars, multipurpose passen-
ger vehicles, and trucks that have a gross
vehicle weight rating (GVWR) of 10,000
pounds or less.
Light truck (LT) tire: a tire designated by
its manufacturer as primarily intended for
use on lightweight trucks or multipurpose
passenger vehicles.
Tread: portion of a tire that comes into
contact with the road.
Tread rib: a tread section running circum-
ferentially around a tire.
Tread separation: pulling away of the
tread from the tire carcass.
Carcass: the tire structure, except tread
and sidewall rubber which, when inflated,
bears the load.
Sidewall: portion of a tire between the
tread and bead.
Section width: the linear distance between
the exteriors of the sidewalls of an
inflated tire, excluding elevations due to
labeling, decoration, or protective bands.
Bead: the part of the tire that is made of
steel wires, wrapped or reinforced by ply
cords and that is shaped to fit the rim.
Ply: a layer of rubber-coated parallel
cords.
Cord: the strands forming the plies in the
tire.
Rim: a metal support for a tire or a tire
and tube assembly upon which the tire
beads are seated.
Rim diameter: nominal diameter of the
bead seat.
Groove: the space between two adjacent
tread ribs.
Tire Markings
1- Size Designation
2- Service Description
3- Maximum Load
4- Maximum Pressure
5- U.S. DOT Safety Standards Code
(TIN)
6- Treadwear, Traction and Temperature
Grades
Size Designation
EXAMPLE: P215/65R15
Passenger car tire size based
P
on U.S.A. design standards
Section width in millimeters
215
(mm)
Vehicle care and maintenance
Tires
9
9-13