13-8Consumer information and Reporting safety defects/Tire information
.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. .
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 2. . 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.
13-14Consumer information and Reporting safety defects/Uniform tire quality grading standards
XXX kg or XXX lbs. 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-
able cargo and luggage load capa-
city is 650 lbs. (1,400 750 (5 6
150) = 650 lbs).
5. Determine the combined weight
of luggage and cargo being loaded
on the vehicle. That weight may not
safely exceed the available cargo
and luggage load capacity calcu-
lated in Step 4. 6. If your vehicle will be towing a
trailer, load from your trailer will be
transferred to your vehicle. Consult
this manual to determine how this
reduces the available cargo and
luggage load capacity of your ve- hicle. Uniform tire quality grading standards
This information indicates the rela-
tive performance of passenger car
tires in the area of treadwear,
traction, and temperature resis-
tance. This is to aid the consumer
in making an informed choice in the
purchase of tires.
Quality grades can be found where
applicable on the tire sidewall be-
tween tread shoulder and maxi-
mum section width. For example:
Treadwear 200 Traction AA Tem-
perature A
The quality grades apply to new
pneumatic tires for use on passen-
ger cars. However, they do not
apply to deep tread, winter type
snow tires, space-saver or tempor-
ary use spare tires, tires with
nominal rim diameters of 12 inches
or less, or to some limited produc-
tion tires.
All passenger car tires must con-form to Federal Safety Require-
ments in addition to these grades. &
Treadwear
The treadwear grade is a compara-
tive rating based on the wear rate of
the tire when tested under con-
trolled conditions on a specified
government test course.
For example, a tire graded 150
would wear one and one-half (1-
1/2) times as well on the govern-
ment course as a tire graded 100.
The relative performance of tires
depends upon the actual conditions
of their use, however, and may
depart significantly from the norm
due to variations in driving habits,
service practices and differences in
road characteristics and climate. & Traction AA, A, B, C
The traction grades, from highest to
lowest, are AA, A, B and C. Those
grades represent the tire ’s ability to
stop on wet pavement as measured
under controlled conditions on spe-
