Tire alignment is a term that refers to the position of each tire and/or wheel relative to your car and all your other tires. When properly aligned, your tires point in precisely the same direction, moving your vehicle over the road as smoothly and efficiently as possible.
Why is Tire Alignment So Important?
Picture a bicycle. Ideally, the entire frame, handle bar assembly, and both tires are “pointing straight ahead.” But if the front tire of the bike is suddenly turned, let’s say, 10 degrees left of the direction the handle bars are pointing, the bike would be very difficult to steer as designed. Also, the right side of the front tire would wear prematurely as it was “pushed” along the pavement.
Likewise, all four of your car’s tires need to “point straight ahead” to roll down the road as efficiently as possible. When your tires are not properly aligned, steering is more difficult. Misaligned tires also “fight” each other constantly. Rather than moving forward in unison, each tire pulls in its own separate direction. Even if that direction is only slightly different from the other tires, over time your fuel economy will decrease, steering and suspension components may be damaged, and your tires will wear quicker and unevenly.
What Does a Tire Alignment Include?
The purpose of a tire alignment is to adjust the angles of your tires so they are both perpendicular to the road and parallel to each other. At Mountain View Tire & Auto Service we use sensitive computerized tire alignment equipment to measure all adjustable and non-adjustable alignment angles. (Non-adjustable angles that are off require repair or replacement of the suspension component.)
The four most common adjustable angles are:
This term refers to the direction that your tires tilt toward or away from one another when viewed from the top. Tires that "toe-in" point toward one another. Tires that "toe-out" point away from each other. When it comes to stopping premature tire wear, toe is the angle we’re most concerned with.
This term refers to the direction that your tires tilt toward or away from one another when viewed from the front. Tires that tilt in toward the vehicle have "negative camber." Wheels that tilt away from the vehicle have "positive camber."
This term refers to the angle of the steering axis in relation to an imaginary vertical line that runs through the center of the tire when viewed from the side. "Positive caster" is the term used when the vertical line is tilted toward the rear. If it's tilted forward, we call it "negative caster." The proper caster angle stabilizes your car and allows for better steering.
This term refers to the relationship of all four tires to each other, as well as their relationship to an imaginary center line that runs from bumper to bumper. The term "thrust line" refers to the direction in which the rear tires are pointed. Thrust angle is correctable on cars with adjustable rear suspensions. If your vehicle has a non-adjustable suspension, thrust angle is compensated for by aligning the front tires to the rear tires.