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Keep your tires inflated to the recommended tire pressure
on the VIN decal (found on the
front rail of your trailer). Check the tire pressure before each
trip. Failure to maintain correct tire pressure may result in
tire failure and loss of control, which could cause serious
injury or death.
Measuring and Adjusting Air
Pressure to achieve Proper Inflation
The recommended tire inflation pressure that
vehicle manufacturers provide reflects the proper
psi when a tire is cold. The term cold does not
relate to the outside temperature. Rather, a cold
tire is one that has not been driven on for at least
3 hours. When you drive, your tires get warmer,
causing the air pressure within them to increase.
Therefore, to get an accurate tire pressure reading
you must measure tire pressure when the tires are
cold or compensate for the extra pressure in warm
tires.
Before each trip, check the air pressure of each
tire. Be sure to check the air pressure in the spare
tire as well.
Adverse safety consequences of
under Inflation
Under-inflation of the tire only wear out the tire
prematurely, but can also cause the tire to flex
and to overheat quickly. Overheating of the tires
can cause tread separation and tire failure. Tire
separation or tire failure could lead to loss of
control of the trailer and could lead to an accident.
Keep your tires inflated to the recommended tire pressure
on the VIN decal (found on the front of your trailer). Check
the tire pressure before each trip.
Maintaining Proper Tire Pressure
Locate the recommended tire pressure on the
vehicle’s tire information placcard, certification
label or in the owners manual.
Keep your tires inflated to the recommended tire
pressure on the VIN decal (found on the front of
your trailer). Check the tire pressure before each
trip.
Record the tire pressure on all tires.
If the tire pressure is too high in any of the tires,
slowly release air by gently pressing on the tire
valve stem with the edge of you tire gauge until
you get to the correct pressure.
If the tire pressure is too low, note the difference
between the measured tire pressure and the
correct tire pressure. These ”missing” pounds of
pressure are what you will need to add.
At a service station, add the missing pounds of air
pressure to each tire that is under inflated.
Check all the tires to make sure they have the
same air pressure (except in cases in which the
front and rear tires are supposed to have different
amounts of pressure).
If you have been driving your vehicle and think a
tire is under inflated, fill it to the recommended
cold inflation pressure indicated on your vehicle’s
tire information placard or certification label. While
your tire may still be slightly under inflated due to
the extra pounds of pressure in the warm tire, it is
safer to drive with air pressure that is lightly lower
the vehicle manufacturer’s recommended cold
inflation pressure than to drive with a significantly
under inflated tire. Since this is a temporary
WARNING
!
WARNING
!
fix, don’t forget to recheck and adjust the tire’s
pressure when you can obtain a cold reading.
Tire Fundamentals
Federal law requires tire manufacturers to
place standardized information on the sidewall of
all tires. This information identifies and describes
the fundamental characteristics of the tire and
also provides a tire identification number for safety
standard certification and in case of a recall.
Tire Information
There are many markings found on the
Sidewall of a tire. They are placed there by the tire
manufacturer.
ST-Indicates the tire is for trailer use only.
Next Number– This three digit number gives the
width in millimeters of the tire from sidewall edge
to sidewall edge. In general, the larger the number,
the wider the tire.
Next Number– This two digit number, known as
the aspect ratio, gives the tire’s ratio of height to
width. Numbers of 70 or lower indicate a short
sidewall for improved steering response and better
overall handling on dry pavement.
R– The “R” stands for radial. Radial ply
construction of tires has been the industry
standard for many years.
Next Number– This two-digit number is the wheel
or rim diameter in inches.
If you change your wheel size, you will have to
purchase new tires to match the new wheel
diameter.
U.S. DOT Tire Identification Number-This begins
with the letters “DOT” and indicates that the
tire meets all federal standards. The next two
numbers or letters are the plant code where it
was manufactured, and the last four numbers
represent the week and year the tire was built. For
example, the numbers 3197 means the
31st week of 1997. The other numbers are
marketing codes used at the manufacturer’s
discretion.
This information is used to contact consumers if a
tire defect requires a recall.
Tire Ply Composition and Materials Used– The
number of plies indicates the number of layers of
rubber-coated fabric in the tire. In general, the
greater the number of plies, the more weight a tire
can support. Tire manufacturers also must indicate
the materials in the tire, which include steel, nylon,
polyester and others.
Maximum Load Rating– This number indicates the
maximum load in kilograms and pounds that can
be carried by the tire.
Maximum Permissible Inflation Pressure-This
number is the greatest amount of air pressure that
should ever be put in the tire under normal driving
conditions.
RADIAL TIRES
(Using a ST205/75R14C as an example)
ST
Special Trailer type tire
205 Nominal width of the tire in millimeters
(205 millimeters in this example)
75
Aspect ratio of height to width)
(75% in this example)
R
Radial Tire
14
Size of Wheel (14” in this example)
C
Load Range Rating
Tire size labeling information
Tire Size
Your trailer will be equipped with radial tires. It
is important to understand the tire labeling on
your tire when selecting tire or replacement tires
for your trailer. To maintain tire safety, purchase
new tires that are the same size as the vehicle’s
original tires or another size recommended by the
manufacturer. Look at the tire information placard,
the owner’s manual, or the sidewall of the tire you
are replacing to find this information. If you have
any doubt about the correct size to choose, consult
with the tire dealer.
