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Ok, I have heard and read other places that a tire was at its proper inflation by inflating it to the max psi on the tire. That is actually wrong and quite unsafe. The following is an article found on

Inflation Pressure
Proper inflation pressure is essential for achieving maximum performance and mileage. Improper tire inflation pressure can cause severe internal tire damage, which can lead to sudden tire failure and resulting in serious personal injury or death.

Improper inflation pressure may result in rapid or irregular wear. Pressures should always be checked when the tires are cold and at least monthly. Under normal tire operation, approximately 1psi of tire pressure will escape every month. Also, for every 10 degrees F change in ambient temperature, tire pressure will change by approximately 1psi.

Vehicle manufacturers list recommended tire pressures for original vehicle tires in the owner's manual or on a placard on the end of the driver's side door or in the glove box.

For continuous high speed driving, tire pressures should be increased by 3 to 5psi above the normal cold inflation recommended. However, for passenger tires, never exceed the maximum inflation pressure molded on the sidewall. The inflation pressure for light truck tires may exceed that molded on the tire by 10psi. Any recommended front to rear pressure differential should be maintained.

Recommended Inflation Pressure
Many people ask "what air pressures do you (meaning tire companies) recommend for cars under normal conditions?" The answer is "we recommend what the vehicle manufacturer recommends." Many people mistakenly believe the only reason vehicle manufacturers recommend certain air pressures is for ride comfort.

What criteria do the car manufacturers use to determine inflation recommendations?
Load capacity
Traction, wear
Fuel economy/Rolling resistance

.....are all correct. But, consider another question:

"Why did Ford recommend 30 in the front and 34 in the rear on a 1997 Crown Victoria?"
The additional air stiffens the sidewall and makes it more stable. In order to achieve the handling, tracking, and other driving characteristics, one of the things the manufacturer can do is balance front to rear handling by adjusting the tire pressures. In adding the same air pressure in the front as the rear you will change the handling characteristics from what the manufacturer intended. Quite a few station wagons and light trucks have different pressures for the front and rear. But, it's not just station wagons and light trucks; it's also Porsches, Nissans, Corvettes, Hondas, and BMW's to name just a few.

Tire Safety

That site also has alot of good tire information as well

Drive Safe,

107 Posts
Thanks. This was a point of confusion for me. It'd be nice if there was a min tire pressure listed too on the tires.
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