Tire Sizing Chart
EXAMPLE:
Example Size Designation: P215/65R15XL 95H, 215/65R15 96H, LT235/85R16C, T145/80D18 103M, 31x10.5 R15 LT P= Passenger car tire size based on U.S. design standards, or
....blank.... = Passenger car tire based on European design standards, or
LT = Light truck tire based on U.S. design standards, or
TorS= Temporary spare tire or
31 = Overall diameter in inches (in)
215, 235, 145 = Section width in millimeters (mm)
65, 85, 80 = Aspect ratio in percent (%)
– Ratio of section height to section width of tire, or
10.5 = Section width in inches (in)
R = Construction code
–R means radial construction, or
– D means diagonal or bias construction
15, 16, 18 = Rim diameter in inches (in)
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STARTING AND OPERATING 367
Gross Axle Weight Rating (GAWR)
The GAWR is the maximum capacity of the front and rear
axles. Distribute the load over the front and rear axles
evenly. Make sure that you do not exceed either front or
rear GAWR. Refer to “Vehicle Loading/Vehicle Certifica-
tion Label” in “Starting And Operating” for further infor-
mation.
WARNING!
It is important that you do not exceed the maximum
front or rear GAWR. A dangerous driving condition
can result if either rating is exceeded.
Tongue Weight (TW)
The tongue weight is the downward force exerted on the
hitch ball by the trailer. You must consider this as part of
the load on your vehicle.
Frontal Area
The frontal area is the maximum height multiplied by the
maximum width of the front of a trailer.
Trailer Sway Control
The trailer sway control is a telescoping link that can be
installed between the hitch receiver and the trailer tongue
that typically provides adjustable friction associated with
the telescoping motion to dampen any unwanted trailer
swaying motions while traveling.
Weight-Carrying Hitch
A weight-carrying hitch supports the trailer tongue weight,
just as if it were luggage located at a hitch ball or some
other connecting point of the truck. These kind of hitches
are the most popular on the market today and they are
commonly used to tow small- and medium-sized trailers.
Weight-Distributing Hitch
A weight-distributing system works by applying leverage
through spring (load) bars. They are typically used for
heavier loads to distribute trailer tongue weight to the tow
vehicle’s front axle and the trailer axle(s). When used in
accordance with the manufacturer’s directions, it provides
for a more level ride, offering more consistent steering and
brake control, thereby enhancing towing safety. The addi-
tion of a friction/hydraulic sway control also dampens
sway caused by traffic and crosswinds and contributes
positively to tow vehicle and trailer stability. Trailer sway
404 STARTING AND OPERATING
