Page 576 of 620

576 6-1. Specifications
Tire related termMeaning
Normal occupant 
weight 150 lb. (68 kg) times the number of occupants 
specified in the second column of Table 1
* that 
follows
Occupant distribution Distribution of occupants in a vehicle as speci-
fied in the third column of Table 1
* below
Production options 
weight The combined weight of installed regular pro-
duction 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 brakes, ride levelers, roof rack, heavy duty 
battery, and special trim
Rim A metal support for a tire or a tire and tube 
assembly upon which the tire beads are seated
Rim diameter
(Wheel diameter) Nominal diameter of the bead seat
Rim size designation Rim diameter and width
Rim type designation The industry manufacturer's designation for a 
rim by style or code
Rim width Nominal distance between rim flanges
Vehicle capacity 
weight (Total load 
capacity) The rated cargo and luggage load plus 150 lb. 
(68 kg) times the vehicl
e's designated seating 
capacity
Vehicle maximum load 
on the tire The 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 The load on an individual tire that is determined 
by distributing to each axle its share of curb 
weight, accessory weight, and normal occu-
pant weight (distributed in accordance with 
Ta b l e  1
* below), and dividing by two 
         
        
        
     
        
        Page 578 of 620

578 6-1. Specifications
Tire related termMeaning
Innerliner separation The parting of the innerliner from cord material 
in the carcass
Intended outboard 
sidewall (a) The sidewall that contains a whitewall, 
bears white lettering, or bears manufac-
turer, brand, and/or model name molding 
that is higher or deeper than the same 
molding on the other sidewall of the tire, or
(b) The outward facing sidewall of an asym- metrical tire that has a particular side that 
must always face ou tward when mounted 
on a vehicle
Light truck (LT) tire A tire designated by its manufacturer as prima-
rily intended for use on lightweight trucks or 
multipurpose passenger vehicles
Load rating The maximum load that a tire is rated to carry 
for a given inflation pressure
Maximum load rating The load rating for a tire at the maximum per-
missible inflation pressure for that tire
Maximum permissible 
inflation pressure The maximum cold inflation pressure to which 
a tire may be inflated
Measuring rim The rim on which a tire is fitted for physical 
dimension requirements
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 eleva-
tions due to labeling, decorations, or protective 
bands or ribs
Passenger car tire A tire intended for use on passenger cars, mul-
tipurpose passenger vehicles, and trucks, that 
have a gross vehicle weight rating (GVWR) of 
10,000 lb. or less. 
         
        
        
     
        
        Page 579 of 620

579
6-1. Specifications
6
Vehicle specifications
Tire related termMeaning
Ply A layer of rubber-coated parallel cords
Ply separation A parting of rubber compound between adja-
cent plies
Pneumatic tire A mechanical device made of rubber, chemi-
cals, fabric and steel or
 other materials, that, 
when mounted on an automotive wheel, pro-
vides the traction and contains the gas or fluid 
that sustains the load
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
Reinforced tire  A tire designed to operate at higher loads and 
at higher inflation pressures than the corre-
sponding standard tire
Section width The linear distance between the exteriors of 
the sidewalls of an inflated tire, excluding ele-
vations due to labeling, decoration, or protec-
tive bands
Sidewall That portion of a tire between the tread and 
bead
Sidewall separation The parting of the rubber compound from the 
cord material in the sidewall
Snow tire A tire that attains a traction index equal to or 
greater than 110, compared to the ASTM E- 
1136 Standard Reference Test Tire, when 
using the snow traction test as described in 
ASTM F-1805-00, Standard Test Method for 
Single Wheel Driving Traction in a Straight Line 
on Snow-and Ice-Covered Surfaces, and which 
is marked with an Alpine Symbol ( ) on at 
least one sidewall
Te s t  r i m The rim on which a tire is fitted for testing, and 
may be any rim listed as appropriate for use 
with that tire