Your vehicle's proper tire-inflation pressure is listed either in the owner's manual, printed on a special label on the driver's door, or displayed within a special label in the driver's doorjamb, or B-pillar. The maximum psi imprinted on a tire only denotes the maximum safe pressure for that tire. It is not your vehicle's proper tire-inflation pressure.
"Proper tire pressure provides you and your vehicle with improved performance," says Edmonds. "We're not talking about high-speed driving and performance in that sense of the word, but rather the ability of your tires to allow you to better control your vehicle, particularly in emergency situations -- emergency stops, avoidance maneuvers and good traction on a wet road."
Underinflated tires make a vehicle react slower because the tires are not well supported by their sidewalls, he says, noting also that underinflation can lead to a situation where the car is more easily upset, causing it to pitch more whenever you change direction. In addition, when a car's tires are underinflated, normal driving can build up much more heat inside the tire. Excessive heat deteriorates components within the tire and its sidewall and can lead to catastrophic tire failure, a blowout, as well.
Since 2007, the U.S. government has mandated all new vehicles have built-in tire-pressure monitoring systems, but these systems typically warn of a tire-pressure drop of 20 percent from its recommended pressure.
A 20 percent to 25 percent decrease from a recommended pressure of 32 psi is significant. That's 8 pounds of pressure -- past the point of likely tire damage, says Edmonds. "So, even if your car has tire-pressure monitoring, it's still a very good thing to check your tire pressure on your own with a quality gauge at least once a month."
A is AlignmentOften referred to simply as a "wheel alignment," this procedure actually includes measuring and adjusting suspension angles and suspension components, Edmonds says, and greatly influences the operation of the vehicle's tires.
Out-of-alignment means the suspension and steering systems are not operating at the proper angles, conditions often caused by normal spring sag or suspension wear in the ball joints and bushings, for example. On older vehicles, impact with a pothole or curb often is the cause.
Incorrect alignment settings will usually result in more rapid tire wear. Therefore, alignment should be checked whenever new tires or suspension components are installed and anytime unusual tire-wear patterns appear. "And alignment should also be checked after the vehicle has encountered a major road hazard or curb," says Zielinski.
The different types of alignment offered today are front-end, thrust-angle and four-wheel. During a front-end alignment, only the front axle's angles are measured and adjusted. Front-end alignments are generally fine for vehicles with a solid rear axle.
On vehicles with four-wheel independent suspension or front-wheel-drive vehicles with adjustable rear suspensions, the appropriate alignment is a four-wheel alignment. This procedure squares the vehicle like a thrust-angle alignment and includes measuring and adjusting the rear axle angles as well as the front.
R is RotationRotation is also important. Tires generally need to be rotated every 5,000 miles to 8,000 miles. Tires tend to wear differently at each point on a vehicle, and when you rotate your tires properly and according to a set schedule, you promote even wear, getting the most out of your tire investment.