.Passenger car tire
A tire intended for use on passen-
ger cars, multipurpose passenger
vehicles, 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 rub-
ber, 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 theload. . 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. .
Rim type designation
The industry of manufacturer ’s des-
ignation for a rim by style or code. . Rim width
Nominal distance between rim flanges. . Section width
The linear distance between the
exteriors of the sidewalls of an
inflated tire, excluding elevations
due to labeling, decoration, or
protective bands. . Sidewall
That portion of a tire between the
tread and bead.. Sidewall separation
The parting of the rubber com-
pound from the cord material in
the sidewall.. Test rim
The rim on which a tire is fitted for
testing, and it may be any rim listed
as appropriate for use with that tire.. Tread
That portion of a tire that comes
into contact with the road.
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13-8Consumer information and Reporting safety defects
. Tread rib
A tread section running circumfer-
entially around a tire. . Tread separation
Pulling away of the tread from the
tire carcass. . Treadwear indicators (TWI)
The projections within the principal
grooves designed to give a visual
indication of the degrees of wear of
the tread. . Vehicle capacity weight
The rated cargo and luggage load
plus 150 lbs (68 kg) times thevehicle ’s designated seating capa-
city. . Vehicle maximum load on the
tire
Load on an individual tire that is
determined by distributing to each
axle its share of the maximum
loaded vehicle weight and dividing
by two. . 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 oc-
cupant weight (distributed in accor-
dance with Table 1 that is ap-
pended to the end of this section)
and dividing by 2.
. Wheel-holding fixture
The fixture used to hold the wheel
and tire assembly securely duringtesting.
13-10Consumer information and Reporting safety defects
Replace any damaged or un-
evenly worn tires at the time of
rotation. After tire rotation, adjust
the tire pressures and make sure
the wheel nuts are correctly tigh-
tened. For information about the
tightening torque and tightening
sequence for the wheel nuts, referto “Flat tires ”F 9-6 .
& Vehicle load limit –how to
determine
The load capacity of your vehicle is
determined by weight, not by avail-
able cargo space. The load limit of
your vehicle is shown on the
vehicle placard attached to the
driver ’s side B-pillar. Locate the
statement “The combined weight
of occupants and cargo should
never exceed XXX kg or XXX lbs ”
on your vehicle ’s placard.
The vehicle placard also shows
seating capacity of your vehicle.
The total load capacity includes the
total weight of driver and all pas-
sengers and their belongings, any cargo, any optional equipment such
as a trailer hitch, roof rack or bike
carrier, etc., and the tongue load of
a trailer. Therefore cargo capacity
can be calculated by the followingmethod.
Cargo capacity = Load limit
(total
weight of occupants + total weight
of optional equipment + tongue
load of a trailer (if applicable))
For information about vehicle load-
ing, refer to “Loading your vehicle ”
F 8-12 .
For information about towing capa-
city and weight limits, refer to“ Trailer towing ”F 8-18 .
! Calculating total and load ca-
pacities varying seating con-
figurations
Calculate the available load capa-
city as shown in the following
examples: Example 1A
Vehicle capacity weight of the
vehicle is 900 lbs (408 kg), which
is indicated on the vehicle placard
with the statement
“The combined
weight of occupants and cargo
should never exceed 900 lbs or
408 kg ”.
For example, if the vehicle has one
occupant weighing 154 lbs (70 kg)
plus cargo weighing 662 lbs (300kg).
1.Calculate the total weight.
2.Calculate the available load ca-
pacity by subtracting the total
weight from the vehicle capacity
weight of 900 lbs (408 kg).
3. The result of step 2 shows that a
further 84 lbs (38 kg) of cargo can
be carried. Example 1B
For example, if a person weighing
176 lbs (80 kg) now enters the
same vehicle (bringing the number
of occupants to two), the calcula-
tions are as follows. 1.
Calculate the total weight.
2.Calculate the available load ca-
pacity.
3. The total weight now exceeds
the capacity weight by 92 lbs (42
kg), so the cargo weight must be
reduced by 92 lbs (42 kg) or more.
Example 2A
Vehicle capacity weight of the
vehicle is 900 lbs (408 kg), which
is indicated on the vehicle placard
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13-12Consumer information and Reporting safety defects
with the statement “The combined
weight of occupants and cargo
should never exceed 408 kg or
900 lbs ”.
For example, the vehicle has one
occupant weighing 165 lbs (75 kg)
plus cargo weighing 375 lbs (170
kg). In addition, the vehicle is fitted
with a trailer hitch weighing 22 lbs
(10 kg), to which is attached a
trailer weighing 1,764 lbs (800 kg).
10% of the trailer weight is applied
to the trailer tongue (i.e. Tongue
load = 176 lbs (80 kg)). 1. Calculate the total weight.
2.Calculate the available load ca-
pacity.
3. The result of step 2 shows that a
further 162 lbs (73 kg) of cargo can
be carried.
Example 2B
For example, if a person weighing
143 lbs (65 kg) and a child weighing
40 lbs (18 kg) now enter the same
vehicle (bringing the number of occupants to three), and a child
restraint system weighing 11 lbs (5
kg) is installed in the vehicle for the
child to use, the calculations are asfollows. 1.
Calculate the total weight.
2.Calculate the available load ca-
pacity.
3.The total weight now exceeds
the capacity weight by 32 lbs (15
kg), so the cargo weight must be
reduced by 32 lbs (15 kg) or more. & Determining compatibility of
tire and vehicle load capaci- ties
The sum of four tires ’maximum
load ratings must exceed the max-
imum 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 ( “GAWR ”). 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 Rat-
ing (GAWR). The GVWR and eachaxle ’s GAWR are shown on the
vehicle certification 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 vehi-cle
’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 tires
Overloading could affect vehicle
handling, stopping distance, and
vehicle and tire performance in the
following ways. 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 body parts 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 Cor-
rect Load Limit
1. Locate the statement “The com-
bined weight of occupants and
cargo should never exceed XXXpounds ”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 kilograms or XXX pounds. 4. The resulting figure equals the
available amount of cargo and
luggage load capacity. For exam-
ple, 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-
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