This section provides an understanding of the many factors essential to proper tyre care and service of vehicles.
Tyre Inflation Pressures
Tyres are designed and built with great care to provide thousands of miles of excellent service. But for maximum benefit they must be maintained properly.
The most important factors in tyre care are:
- Proper Inflation Pressure
- Proper Vehicle Loading
- Proper tyre Wear
- Regular Inspection
- Good Driving Habits
- Vehicle Condition
The Benefits of Proper Inflation
With the right amount of air pressure, you will achieve optimum tyre performance. This means your tyres wear longer, save fuel and help prevent accidents. The "right amount" of air is the pressure specified by the vehicle manufacturer, which may be different on the front than the rear tyres on your particular model car or light truck. The correct air pressure is shown on the tyre placard (or sticker) attached to the vehicle door edge, door post, glove box door or fuel door. If your vehicle doesn't have a placard, check the owner's manual or consult with the vehicle manufacturer, tyre manufacturer or your local tyre dealer for the proper inflation.
The tyre placard tells you the maximum vehicle load, the cold tyre air pressures and the tyre size recommended by the vehicle manufacturer.
If you don't take proper care of your tyres , the results can be serious. Most tyre companies are either supplying a handbook or are molding a safety warning right onto the tyre sidewall. A typical warning is shown on this page.
As you see, it points out that serious injury may result from tyre failure due to underinflation or overloading. Motorists are strongly advised to follow the vehicle owner's manual or the tyre placard in the vehicle for proper inflation and loading.
Only specially trained persons should mount or demount tyres . An explosion of a tyre and wheel assembly can result from improper or careless mounting procedures.
Persons who do mount tyres must have the right equipment, the right training and the right information before proceeding. Never exceed 40 psi to seat the beads. Always use a restraining device when mounting a tyre on a rim, and be sure to stay back from the tyre when inflating it. Make sure to follow the inflation instructions. Contact the Rubber Manufacturers Association at (202) 682-4800 for proper mounting and demounting information.
Remember, mounting and demounting tyres and wheels should be left to skilled professionals who are aware of the safety hazards involved and who have the proper tools and equipment to do the job safely.
Always replace a tyre with another tyre of exactly the same bead diameter designation and suffix letters.
For example: A 16" tyre goes on a 16" rim. Never mount a 16" tyre on a 16.5" rim. A 16.5" tyre goes on a 16.5" rim. Never mount a 16.5" tyre on a 16" rim.
While it is possible to pass a 16" diameter tyre over the lip or flanges of a 16.5" size diameter rim, it cannot be inflated enough to position itself against the rim flange. If an attempt is made to seat the tyre bead by inflating, the tyre bead will break with explosive force and could cause serious injury or death.
Your Own tyre Pressure Gauge
It is difficult to tell just by looking at radial tyres whether they are underinflated. It is important that tyres be properly inflated. Failure to maintain correct inflation pressures may result in rapid wear and uneven tread wear, improper vehicle handling and excessive heat buildup which may result in tyre failure. (Evidence of air loss or repeated underinflation requires tyre removal and expert inspection.)
Air pressure enables a tyre to support the load, so proper inflation is critical. It is impossible to determine whether tyres are properly inflated just by looking at them (see photo). That's why it's important to check your tyres using an accurate tyre gauge which can be purchased at your tyre dealer, auto supply store or other retailer.
Purchase an accurate tyre gauge from your tyre dealer, auto supply store or other retailer.
Check tyre inflation pressure (including the spare) at least once a month and before every long trip. tyres must be checked when they are cold; that is, before they have been run a mile. If you must drive over one mile for air, before you leave home, measure the cold inflation pressure of each tyre and record the actual under-inflation amount for each tyre .
Upon arriving at the service station, measure the inflation pressure of each tyre again, then inflate the warm tyre (s) to a level equal to the warm pressure plus the underinflated amount you measured when the tyre was cold. If the cold tyre inflation pressure matches the placard recommendation, then no further adjustment is necessary for the warm tyre .
When operating a vehicle equipped with radial tyres , it is difficult to notice when a tyre has lost air, or is near flat.
tyres lose air normally through the process of permeation. Changes in outdoor temperature can affect the rate in which your tyre loses air. This change is more pronounced in hot weather. Generally speaking, a tyre may lose one or two pounds of air per month in cool weather, and even more in warmer weather. Underinflation is the leading cause of tyre failure, so check inflation pressure regularly.
Never "bleed" or reduce air pressure when tyres are hot. It is normal for pressures to build up as a result of driving.
Make sure all tyre valves and extensions are equipped with valve caps to keep out dirt and moisture. Have a new valve stem assembly installed whenever a tyre is replaced.
Underinflation or overloading creates excessive stresses and heat, and can lead to tyre failure. This could result in vehicle damage and/or serious injury or death. Proper inflation extends tyre life and saves fuel.
Maintain the inflation pressure listed in the vehicle owner's manual or on the tyre placard.
Proper Vehicle Loading
In addition to showing the vehicle manufacturer's recommended cold inflation pressure, the tyre placard also shows the maximum load of the vehicle. Do not overload your vehicle. Remember, baggage carried on top of any vehicle counts as additional load.
If you are towing a trailer, remember that some of the weight of the loaded trailer transfers to the towing vehicle. This reduces the load that can safely be placed in the towing vehicle. The only sure way to prevent overload is to weigh, axle by axle, the fully-loaded vehicle on reliable platform scales. Vehicle weighing procedures are available in the UKTOW.com.
Load and inflation information for popular auto tyre sizes may be obtained from your local tyre dealer.
Information displayed on the tyre sidewall
How Cold Temperature Affects Tyres
Tyre Anantomy, Design and Construction
Replacement Tyre Selection