17 | Page
www.mdcusa.co m
Ph: 833-632-8721
Page | 17
Tire Safety – Everything Rides on it.
The National Traffic Safety Administration (NHTSA) has published a brochure (DOT HS 809 361) that
discusses all aspects of Tire Safety, as required by CFR 575.6. This brochure is reproduced in part below. It
can be obtained and downloaded from NHTSA, free of charge, from the following web site:
http://www.nhtsa.dot.gov/cars/rules/TireSafety/ridesonit/tires_index.html
Studies of tire safety show that maintaining proper tire pressure, observing tire and vehicle load limits (not
carrying more weight in your vehicle than your tires or vehicle can safely handle), avoiding road hazards, and
inspecting tires for cuts, slashes, and other irregularities are the most important things you can do to avoid
tire failure, such as tread separation or blowout and flat tires. These actions, along with other care and
maintenance activities, can also:
• Improve vehicle handling.
• Help protect you and others from avoidable breakdowns and accidents.
• Improve fuel economy.
• Increase the life of your tires.
This booklet presents a comprehensive overview of tire safety, including information on the following topics:
• Basic tire maintenance
• Uniform Tire Quality Grading System
• Fundamental characteristics of tires
• Tire safety tips.
Use this information to make tire safety a regular part of your vehicle maintenance routine. Recognize that
the time you spend is minimal compared with the inconvenience and safety consequences of a flat tire or
other tire failure.
Safety First – Basic Tire Maintenance
Properly maintained tires improve the steering, stopping, traction, and load-carrying capability of your vehicle.
Underinflated tires and overloaded vehicles are a major cause of tire failure. Therefore, as mentioned above,
to avoid flat tires and other types of tire failure, you should maintain proper tire pressure, observe tire and
vehicle load limits, avoid road hazards, and regularly inspect your tires.
Finding Your Vehicles Recommended Tire Pressure and Load Limit
Tire information placards and vehicle certification labels contain information on tires and load limits. These
labels indicate the vehicle manufacturer’s information including:
• Recommended tire size
• Recommended tire inflation pressure
• Vehicle capacity weight (VCW–the maximum occupant and cargo weight a vehicle is designed to
carry)
• Front and rear gross axle weight ratings (GAWR– the maximum weight the axle systems are designed
to carry).
Both placards and certification labels are permanently attached to the trailer near the left front.
Understanding Tire Pressure and Load Limits
Tire inflation pressure is the level of air in the tire that provides it with load-carrying capacity and affects the
overall performance of the vehicle. The tire inflation pressure is a number that indicates the amount of air
pressure– measured in pounds per square inch (psi)–a tire requires to be properly inflated. (You will also find
this number on the vehicle information placard expressed in kilopascals (kPa), which is the metric measure
used internationally.) Manufacturers of passenger vehicles and light trucks determine this number based on
the vehicle’s design load limit, that is, the greatest amount of weight a vehicle can safely carry and the
vehicle’s tire size. The proper tire pressure for your vehicle is referred to as the “recommended cold inflation
pressure.” (As you will read below, it is difficult to obtain the recommended tire pressure if your tires are not
cold.) Because tires are designed to be used on more than one type of vehicle, tire manufacturers list the
“maximum permissible inflation pressure” on the tire sidewall. This number is the greatest amount of air
pressure that should ever be put in the tire under normal driving conditions.
To Next Page
Loading...
