Safety and Tire Pressure
While the current concern about high gas prices has highlighted the fuel-economy improvement gained from properly inflated tires, the most important aspect of this issue is vehicle safety. The National Highway Traffic Safety Administration (NHTSA) estimates that underinflated tires are a factor in 660 fatalities and 33,000 crash injuries each year. The NHTSA survey estimated that 27 percent of passenger cars on U.S. roadways are driven with one or more substantially underinflated tire. Moreover, 32 percent of light trucks (SUVs, vans and pickup trucks) are driven with one or more substantially underinflated tire, according to that study.
Our article, "Tire Pressure Monitors, Can You Rely on Them?," graphically illustrates how driving on tires that are underinflated by only 5 psi makes a dramatic difference. When the underinflated tires are then driven on a wet course, the result is frightening — very little rubber is still in contact with the road.
Underinflated tires don't allow the tread to make proper contact with the road and much of the grip is lost. This will affect the handling and braking of the car. Underinflated tires will also heat up as you drive and could eventually lead to a blowout. This heat factor is further amplified if you live in a warm-weather climate and if your vehicle is heavily loaded with passengers or cargo.
Under normal driving conditions, underinflated tires won't significantly affect the driving dynamics of the vehicle. However, if an emergency avoidance maneuver is required and the tires are underinflated, braking is severely reduced and the car's handling is compromised. The result could be the difference between life and death.