brakes SUBARU BRZ 2023 User Guide

Tire Information
397
Consumer Information and Reporting Safety Defects13
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The vehicle placard shows original
tire size, recommended cold tire
inflation pressure on each tire at
maximum loaded vehicle weight,
seating capacity and loading infor-
mation.▼ Adverse safety consequences
of under-inflation
Driving at high speeds with exces-
sively low tire pressures can cause
the tires to flex severely and to
rapidly become hot. A sharp
increase in temperature could
cause tread separation, and failure
of the tire(s). Possible resulting loss
of vehicle control could lead to an
accident.
▼ Measuring and adjusting air
pressure to achieve proper
inflation
Check and, if necessary, adjust the
pressure of each tire (including the
spare) at least once a month and
before any long journey. Check the
tire pressures when the tires are
cold. Use a pressure gauge to adjust the tire pressures to the

specific values. Driving even a short
distance warms up the tires and
increases the tire pressures. Also,
the tire pressures are affected by
the outside temperature. It is best to
check tire pressure outdoors before
driving the vehicle. When a tire
becomes warm, t he air inside it
expands, causing the tire pressure
to increase. Be careful not to
mistakenly release air from a warm
tire to reduce its pressure.
■ Glossary of Tire TerminologyAccessory weight
The combined weight (in excess of
those standard items which may be
replaced) of automatic transmis-
sion, power steering, power brakes,
power windows, power seats, radio,
and heater, to the extent that these
items are available as factory-
installed equipment (whether
installed or not).
 Bead
The part of the tire that is made of
steel wires, wrapped or reinforced by ply cords and that is shaped to fit

the rim.
 Bead separation
A breakdown of the bond between
components in the bead.
 Bias ply tire
A pneumatic tire in which the ply
cords that extend to the beads are
laid at alternate an gles substantially
less than 90 degrees to the
centerline of the tread.
 Carcass
The tire structure, except tread and
sidewall rubber which, when
inflated, bears the load.
 Chunking
The breaking away of pieces of the
tread or sidewall.
 Cold tire pressure
The pressure in a tire that has been
driven less than 1 mile or has been
standing for three hours or more.
 Cord
The strands forming the plies in the
tire.
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Tire Information
399
Consumer Information and Reporting Safety Defects13
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Occupant distribution
Distribution of occupants in a
vehicle as specified in the third
column of Table 1 that is appended
to the end of this section.
 Open splice
Any parting at any junction of tread,
sidewall, or innerliner that extends
to cord material.
 Outer diameter
The overall diameter of an inflated
new tire.
 Overall width
The linear distance between the
exteriors of the sidewalls of an
inflated tire, including elevations
due to labeling, decorations, or
protective bands or ribs.
 Passenger car tire
A tire intended for use on passenger
cars, multipurpose passenger vehi-
cles, and trucks, that have a gross
vehicle weight rating (GVWR) of
10,000 lbs (4,535 kg) or less. 
Ply
A layer of rubber-coated parallel
cords.
 Ply separation
A parting of rubber compound
between adjacent plies.
 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.
 Production options weight
The combined weight of those
installed regular production options
weighing over 5.1 lbs (2.3 kg) in
excess of those standard items
which they replace, not previously
considered in curb weight or acces-
sory weight, including heavy duty
brakes, ride levelers, roof rack,
heavy duty battery, and special trim. 
Radial ply tire
A pneumatic tire in which the ply
cords that extend to the beads are
laid at substantially 90 degrees to
the centerline of the tread.
 Recommended inflation pres-
sure
The cold inflation pressure recom-
mended by a vehicle manufacturer.
 Reinforced tire
A tire designed to operate at higher
loads and at higher inflation pres-
sures than the corresponding stan-
dard tire.
 Rim
A metal support for a tire or a tire
and tube assembly upon which the
tire beads are seated.
 Rim diameter
Nominal diameter of the bead seat.
 Rim size designation
Rim diameter and width.
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Tire Information
404■Determining Compatibility of
Tire and Vehicle Load Capac -
itiesThe sum of four tires’ maximum
load ratings must exceed the
maximum loaded vehicle weight
(“GVWR”). In addition, sum of the
maximum load ratings of two front
tires and of two rear tires must
exceed each axle’s maximum
loaded capacity (“GVWR”). Original
equipment tires are designed to
fulfill those conditions.
The maximum loaded vehicle
weight is referred to Gross Vehicle
Weight Rating (GVWR). And each
axle’s maximum loaded capacity is
referred to Gross Axle Weight
Rating (GAWR). The GVWR and
each axle’s GAWR are shown on
the vehicle certific ation label affixed
to the driver’s door.
The GVWR and front and rear
GAWRs are determined by not only
the maximum load rating of tires but
also loaded capacities of the
vehicle’s suspension, axles and
other parts of the body. Therefore, this means that the

vehicle cannot necessarily be
loaded up to the tire’s maximum
load rating on the tire sidewall.
■ Adverse Safety Conse -
quences of Overloading on
Handling and Stopping and
on TiresOverloading could affect vehicle
handling, stopping distance, vehicle
and tire as shown in the following.
This could lead to an accident and
possibly result in severe personal
injury.
 Vehicle stability will deteriorate.
 Heavy and/or high-mounted
loads could increase the risk of
rollover.
 Stopping distance will increase.
 Brakes could overheat and fail.
 Suspension, bearings, axles and
other parts of the body could break
or experience accelerated wear that
will shorten vehicle life.
 Tires could fail.
 Tread separation could occur. 
Tire could separate from its rim.
■ Steps for Determining
Correct Load Limit1. Locate the statement “The
combined weight of occupants and
cargo should never exceed XXX kg
or XXX lbs.” on your vehicle’s
placard.
2. Determine the combined weight
of the driver and passengers that
will be riding in your vehicle.
3. Subtract the combined weight of
the driver and passengers from
XXX kg or XXX lbs.
4. The resulting figure equals the
available amount of cargo and
luggage load capacity. For
example, if the “
XXX
” amount equals
1,400 lbs (635 kg) and there will be
five 150 lbs (68 kg) passengers in
your vehicle, the amount of avail-
able cargo and luggage load
capacity is 650 lbs (1,400 − 750 (5 ×
150) = 650 lbs).
5. Determine the combined weight
of luggage and cargo being loaded
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