GMC 2008 Envoy - Manual (Page 357)

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 as shown on the tire placard.
See Inflation - Tire Pressure on page 5-64
and Loading Your Vehicle on page 4-34.
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 5-73.
5-63