What is wheel alignment in car?

Answer 1

Wheel alignment, in general, seeks to get the tires on your car as perpendicular to the ground and parallel to each other as possible. This is done by adjusting the angles that your tires sit at. The variables adjusted in an alignment are caster, camber and toe (other adjustments can be made, such as rake, but the three mentioned above are the ones to know).

Caster - the front wheels of your car turn on a pivot, and caster is the angle of this pivot, measured in degrees from the vertical and viewed from the side of the wheel. Caster can be positive or negative, depending on whether the pivot is tilted backward or forwards, respectively. More positive camber tends to make the car more stable in a straight line. If caster is not the same on both sides of the car, the car will tend to pull towards the side with more positive camber.


Camber - this is the angle of the wheel measured from the vertical, but viewed from the front or rear of the car. A wheel that tilts in towards the car is said to have negative camber, and a wheel leaning the opposite way has positive camber. Camber is important because a tire's performance depends heavily on it's angle relative to the road. It has a large impact on a car's handling.


Toe - if a car is viewed from the top down, toe is the amount that the wheels point towards or away from the centerline of the vehicle's track. When the front of a tire points in towards the center of the car, it is said to have toe in. When the opposite is the case, it is said to be toed out. Toe has an effect on tire wear, and how a car handles upon entering turns and in straight lines.


There's a lot more information that you can find about wheel alignment theory and how various alignment settings affect handling. I think that these three elements are a good introduction, though. Hope this helped!