08 Wheels and tires
Glossary of tire terminology
08
324
Terms
The tire suppliers may have additional mark-
ings, notes or warnings such as standard
load, radial tubeless, etc.
•
Tire information placard: A placard
showing the OE (Original Equipment) tire
sizes, recommended inflation pressure,
and the maximum weight the vehicle can
carry.
•
Tire Identification Number (TIN): A
number on the sidewall of each tire pro-
viding information about the tire brand
and manufacturing plant, tire size and
date of manufacturer.
•
Inflation pressure: A measure of the
amount of air in a tire.
•
Standard load: A class of P-metric or
Metric tires designed to carry a maximum
load at 35 psi [37 psi (2.5 bar) for Metric
tires]. Increasing the inflation pressure
beyond this pressure will not increase the
tires load carrying capability.
•
Extra load: A class of P-metric or Metric
tires designed to carry a heavier maxi-
mum load at 41 psi [43 psi (2.9 bar) for
Metric tires]. Increasing the inflation pres-
sure beyond this pressure will not
increase the tire's load carrying capabil-
ity.
•
kPa: Kilopascal, a metric unit of air pres-
sure.
•
PSI: Pounds per square inch, a standard
unit of air pressure.
•
B-pillar: The structural member at the
side of the vehicle behind the front door.
•
Bead area of the tire: Area of the tire
next to the rim.
•
Sidewall of the tire: Area between the
bead area and the tread.
•
Tread area of the tire: Area of the perim-
eter of the tire that contacts the road
when mounted on the vehicle.
•
Rim: The metal support (wheel) for a tire
or a tire and tube assembly upon which
the tire beads are seated.
•
Maximum load rating: a figure indicating
the maximum load in pounds and kilo-
grams that can be carried by the tire. This
rating is established by the tire manufac-
turer.
•
Maximum permissible inflation
pressure: the greatest amount of air
pressure that should ever be put in the
tire. This limit is set by the tire manufac-
turer.
•
Recommended tire inflation pressure:
inflation pressure, established by Volvo,
which is based on the type of tires that
are mounted on a vehicle at the factory.
This information can be found on the tire
inflation placard(s) located on the driver's
side B-pillar and in the tire inflation table
in this chapter.
•
Cold tires: The tires are considered to be
cold when they have the same tempera-
ture as the surrounding (ambient) air. This
temperature is normally reached after the
vehicle has been parked for at least
3 hours.
