Maintenance
9-42
Pneumatic tire
A mechanical device made of rubber,
chemicals, fabric and steel or other
materials, that, when mounted on
an automotive wheel provides the
traction and contains the gas or fluid
that sustains the load.
Pneumatic options weight
The combined weight of installed
regular production options weighing
over 5 lb. (2.3 kg) in excess of the
standard items which they replace,
not previously considered in
curb weight or accessory weight,
including heavy duty breaks, ride
levelers, roof rack, heavy duty
battery, and special trim.
Recommended inflation pressure
Vehicle manufacturer’s
recommended tire inflation pressure
as shown on the tire placard.
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 of
tread remains.
UTQGS
Uniform Tire Quality Grading
Standards is 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.
Vehicle capacity weight
The number of designated seating
positions multiplied by 150 lbs. (68
kg) plus the rated cargo and luggage
load.
Vehicle maximum load on the tire
Load on an individual tire due to curb
and accessory weight plus maximum
occupant and cargo weight.
Vehicle normal load on the tire
Load on an individual tire that is
determined by distributing to each
axle its share of the curb weight,
accessory weight, and normal
occupant weight and dividing by 2.
