Why America Needs More (Tire) Inflation

BOSTON ( TheStreet) — A recent test of more than 3,000 Americans' cars found that less than 10% had all four tires properly inflated, but here's pre-Labor Day look at how you can avoid the problems that high or low tire pressure can cause.

"Tires are the Rodney Dangerfield of cars — they get no respect. They always look round and black no matter what shape they're in, so people say: 'Oh, they look OK," says Dan Zielinski of the Rubber Manufacturers Association , which sponsored the test.

Tire shops working with the RMA in 26 U.S. cities recently checked the air pressure on some 3,300 customers' vehicles and discovered that:

  • only 9% had all four tires properly inflated;
  • 69% had at least one tire underinflated;
  • 22% had at least one tire overinflated;
  • 18% had at least one tire underinflated by at least 8 pounds per square inch, which is enough on many cars to trigger dashboard warning lights (which the RMA figures drivers simply ignored).

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A 2013 RMA survey also found that just one car owner in six properly tests their vehicle's tire pressure, while only one in three checks the spare and half don't know how to recognize a bald tire.

All of that's bad because poorly maintained tires can cause a wide range of problems.

For instance, low tire pressure can worsen fuel efficiency by making a car's engine have to work harder to push the vehicle around. Underinflation also creates extra friction that heats a tire's interior up, degrading the rubber and leading to a shorter lifespan and higher blowout risk.

Conversely, high air pressure means less of a tire's tread will touch the pavement, reducing your car's grip on the road. Overinflation also increases wear on the tread's center area and boosts the odds of a flat tire or blowout if you hit a bump, curb or other road hazard.

Lastly, bald tires have insufficient tread to stop quickly enough if you get into a skid or are about to hit something.

"If you neglect your car's tires and they fail at highway speeds, that can lead to a crash — and a serious one at that," Zielinski says.

To prevent such problems, the RMA advises drivers to check their cars' tires before any Labor Day trips or other long drives, as well as at least once a month throughout the year.

Zielinski says you shouldn't just "eyeball" tires, as they can be as much as 50% underinflated and not look low. Similarly, a car's "Low Tire Pressure" warning light will come on generally only when a tire has dropped to 25% below its recommended air pressure.

Other tips from the RMA: