Tire Safety Information
tires are at the same temperature as the surrounding air, such as when the vehicle
has been parked overnight. Wheel and tire manufacturers recommend adjusting
the air pressure to the trailer manufacturer’s recommended cold inflation pressure,
in pounds per square inch (PSI) stated on the vehicle’s Federal Certification Label
or Tire Placard when the trailer is loaded to its gross vehicle weight rating (GVWR).
If the tires are inflated to less than the recommended inflation level or the GVWR of
the trailer is exceeded, the load carrying capacity of the tire could be dramatically
affected. If the tires are inflated more than the recommended inflation level,
handling characteristics of the tow vehicle/trailer combination could be affected.
Refer to the owner’s manual or talk to your dealer or vehicle manufacturer if you
have any questions regarding proper inflation practices.
Tires can lose air over a period of time. In fact, tires can lose 1 to 3 PSI per month.
This is because molecules of air, under pressure, weave their way from the inside
of the tire, through the rubber, to the outside. A drop in tire pressure could cause
the tire to become overloaded, leading to excessive heat buildup. If a trailer tire is
under-inflated, even for a short period of time, the tire could suffer internal damage.
High speed towing in hot conditions degrades trailer tires significantly. As heat
builds up during driving, the tire’s internal structure starts to breakdown,
compromising the strength of the tire. It is recommended to drive at moderate
speeds.
Statistics indicate the average life of a trailer tire is about five years under normal
use and maintenance conditions. After three years, replacing the trailer tires with
new ones should be considered, even if the tires have adequate tread depth.
Some experts claim that after five years, trailer tires are considered worn out and
should be replaced, even if they have had minimal or no use. This is such a
general statement that it may not apply in all cases. It is best to have your tires
inspected by a tire supplier to determine if your tires need to be replaced.
If you are storing your trailer for an extended period, make sure the tires are fully
inflated to the maximum rated pressure and that you store them in a cool, dry
place, such as a garage. Use tire covers to protect the trailer tires from the harsh
effects of the sun.
3.2 STEPS FOR DETERMINING CORRECT LOAD LIMIT – TRAILER
Determining the load limits of a trailer includes more than understanding the load
limits of the tires alone. On all trailers there is a Federal Certification / VIN label
that is located on the forward half of the left (road) side of the unit. This
certification/VIN label will indicate the trailer’s Gross Vehicle Weight Rating
(GVWR). This is the most weight the fully loaded trailer can weigh. It will also
provide the Gross Axle Weight Rating (GAWR). This is the most a particular axle
can weigh. If there are multiple axles, the GAWR of each axle will be provided.
If your trailer has a GVWR of 10,000 pounds or less, there is a vehicle placard
located in the same location as the certification label described above. This placard
provides tire and loading information. In addition, this placard will show a statement
regarding maximum cargo capacity. Cargo can be added to the trailer, up to the
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