GMC 2006 Envoy Owner's Manual page 417

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 5-65.
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 5-68.
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 4-45.
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 4-45.
5-61