Tire Ratings - Tire's 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. It’s important that you understand that the stated maximum pressure means exactly that. Almost all vehicle manufactures recommend tire pressures less than the maximum stated on the tire because they are matching a pressure they believe best suits the tire on a particular vehicle. This will help insure that the tire’s load capacity, durability, traction and handling capabilities are maximized. To get the recommended pressure you will need to look on the vehicle placard. For vehicles produced between 1968 and 2003, the original tires size(s) and inflation pressures (including the spare) are listed on a vehicle placard (sometimes alternate pressures based on load and/or speed conditions are also provided).
Earlier placards can typically be found on:

• The driver-side door or doorjamb
• Rear passenger doorjamb of Ford sedans
• Fuel filler door
• Glove box or center console door
• The engine compartment

Source: tirerack.com

You might also find it in the vehicle’s owners manual. Proper tire pressure not only helps the tire perform properly for controlling your vehicle it can also save you a good deal of money. It’s estimated that we waste about 3.3million gallons of gas every single day due to improperly inflated tires. Simply looking at your tires is not good enough to know if they are properly inflated. Most radial tires today maintain their shape even if they are over or under inflated. A simple tire pressure check can save you some money (and the environment at the same time). Tire pressure gauges can be purchased in any auto parts stores as well as most department stores with automotive departments. Most types can be purchased for under $10. More accurate digital gauges will range from $10 and $40. The small investment is well worth it.

Tire Ratings and Tire Safety

Maximum Permissible Inflation Pressure

Source: tirerack.com