Tire Safety Information
This portion of the User’s Manual contains tire safety information as required by 49 CFR 575.6.
Section 2.1 contains “Steps for Determining Correct Load Limit - Trailer”.
Section 2.2 contains “Steps for Determining Correct Load Limit – Tow Vehicle”.
Section 2.3 contains a Glossary of Tire Terminology, including “cold inflation pressure”, “maximum inflation
pressure”, “recommended inflation pressure”, and other non-technical terms.
Section 2.4 contains information from the NHTSA brochure entitled “Tire Safety – Everything Rides On It”.
This brochure, as well as the preceding subsections, describes the following items:
Tire labeling, including a description and explanation of each marking on the tires, and information about the
DOT Tire Identification Number (TIN). Recommended tire inflation pressure, including a description and
explanation of:
1.
Cold inflation pressure.
2.
Vehicle Placard and location on the vehicle.
3.
Adverse safety consequences of under inflation (including tire failure).
4.
Measuring and adjusting air pressure for proper inflation.
5.
Tire Care, including maintenance and safety practices.
6.
Vehicle load limits, including a description and explanation of the following items:
7.
Locating and understanding the load limit information, total load capacity, and cargo capacity.
8.
Calculating total and cargo capacities with varying seating configurations including quantitative examples
showing / illustrating how the vehicles cargo and luggage capacity decreases as combined number and size
of occupants’ increases. This item is also discussed in Section 3.
9.
Determining compatibility of tire and vehicle load capabilities.
10.
Adverse safety consequences of overloading on handling and stopping on tires.
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 maximum weight
specified on the placard. The combined weight of the cargo is provided as a single number. In any case, remember:
the total weight of a fully loaded trailer cannot exceed the stated GVWR.
For trailers with living quarters installed, the weight of water and propane also need to be considered. The weight of
fully filled propane containers is considered part of the weight of the trailer before it is loaded with cargo, and is not
considered part of the disposable cargo load. Water however, is a disposable cargo weight and is treated as such. If
there is a fresh water storage tank of 100 gallons, this tank when filled would weigh about 800 pounds. If more
cargo is being transported, water can be off-loaded to keep the total amount of cargo added to the vehicle within the
Gravity Tender V1.0
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