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Proper Tire Pressure: Possible Lifesaver

Many motorists don't pay much attention to it, but tire pressure can be important an important safety factor on the road.

Too little pressure can literally lead to crashes, warns The Early Show consumer correspondent Susan Koeppen.

Proper tire pressure leads to better gas mileage, so it can save you money on gas, she points out. And under-inflated tires tend to wear out more quickly.

But, Koeppen says, the No. 1 reason to keep close tabs on tire pressure is to stay safe.

The National Highway Traffic Safety Administration estimates that 44 million people in the United States are driving with under-inflated tires. They can have a serious impact on a vehicle's handling, its braking abilities, and its performance in wet weather.

Jennifer Stockburger, a Consumer Reports tire safety expert, told Koeppen, "If you're riding on under-inflated tires, you're jeopardizing the safety of that car and your family."

She took Koeppen out on the Consumer Reports test track, to show just how treacherous under-inflated tires can be.

Even slightly under-inflated tires can be a hazard, Koeppen stressed.

Stockburger added: "(Tire inflation is) probably the most critical item, if we were to give advice and say, 'What one thing you can do to keep your car riding and handling?' It would be to check your inflation pressure."

Under normal driving conditions, tires can lose one to two pounds per square inch as air seeps through the rubber and out of the tires. When a tire is significantly under-inflated, 25 percent or more, its sidewalls flex more, and the air temperature inside the tire increases, which raises stress and the risk of failure.

A recent survey of U.S. drivers by the Rubber Manufacturers Association found people getting more complacent about checking tire pressure.

Only 55 percent said they've checked tire pressure within the past month, compared to 70 percent last year, when fuel prices peaked. Some 45 percent of drivers wrongly believe that the correct inflation pressure is the one printed on the tire sidewall. Another 15 percent don't know where to find the correct pressure. Twenty-six percent of drivers wrongly believe that the best time to check their tires is when they're warm, after having been driven for at least a few miles. And only 15 percent of drivers check their tire inflation pressure properly.

To do that:

  • Check it at least once a month.
  • Use the correct inflation pressure recommended by the vehicle manufacturer, not the pressure listed on the tire sidewall. Look at the inside of your door — it will list the correct pressure for each tire. Those numbers are also listed in your owner's manual.
  • Check tires when they're cold or haven't been driven for at least three hours. If you check it right after driving, the pressure will read higher than it really is.
  • Use a tire pressure gauge. They cost as little as a dollar, and you can keep them in your glove compartment.
  • Go to the gas station and have an attendant put in air, or do it yourself. Or, if they have a portable air compressor machine, you can use that. Store it in the garage or in the trunk of your car

    The rubber makers' association survey also found that 71 percent of drivers don't check the tire pressure in their spare tire. It's important to that, as well.

    Each month, nearly seven out of 10 drivers wash their cars, but only one in seven correctly checks their tire pressure.

    The NHTSA estimates more than 23,000 tow-away crashes were due to blowouts or flat tires. Under-inflated tires are blamed in crashes that result in 660 fatalities and 33,000 injuries each year. Twenty-seven percent of passenger cars and 32 percent of light trucks have at least one significantly under-inflated tire.

    For more tips about tire pressure and tire maintenance, go to

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