Occupant Distribution: Designated seating positions.
Outward Facing Sidewall: The side of an asymmetrical
tire that has a particular side that faces outward when
mounted on a vehicle. The side of the tire that contains a
whitewall, bears white lettering, or bears manufacturer,
brand, and/or model name molding that is higher or
deeper than the same moldings on the other sidewall
of the tire.
Passenger (P-Metric) Tire: A tire used on passenger
cars and some light duty trucks and multipurpose
vehicles.
Recommended Inflation Pressure: Vehicle
manufacturer’s recommended tire inflation pressure and
shown on the tire placard. See Inflation - Tire Pressure
on page 5-59 and Loading Your Vehicle on page 4-32.
Radial Ply Tire: A pneumatic tire in which the ply cords
that extend to the beads are laid at 90 degrees to the
centerline of the tread.
Rim: A metal support for a tire and upon which the tire
beads are seated.
Sidewall: The portion of a tire between the tread and
the bead.
Speed Rating: An alphanumeric code assigned to a
tire indicating the maximum speed at which a tire
can operate.
Traction: The friction between the tire and the road
surface. The amount of grip provided.
Tread: The portion of a tire that comes into contact
with the road.
Treadwear Indicators: Narrow bands, sometimes
called wear bars, that show across the tread of a tire
when only 1/16 inch (1.6 mm) of tread remains.
See When It Is Time for New Tires on page 5-61.
UTQGS (Uniform Tire Quality Grading Standards):
A tire information system that provides consumers
with ratings for a tire’s traction, temperature, and
treadwear. Ratings are determined by tire manufacturers
using government testing procedures. The ratings are
molded into the sidewall of the tire. See Uniform
Tire Quality Grading on page 5-64.
Vehicle Capacity Weight: The number of designated
seating positions multiplied by 150 lbs (68 kg) plus
the rated cargo load. See Loading Your Vehicle
on page 4-32.
Vehicle Maximum Load on the Tire: Load on an
individual tire due to curb weight, accessory weight,
occupant weight, and cargo weight.
Vehicle Placard: A label permanently attached to a
vehicle showing the vehicle’s capacity weight and
the original equipment tire size and recommended
inflation pressure. See “Tire and Loading Information
Label” under Loading Your Vehicle on page 4-32.
5-58