Why is wheel alignment necessary?

Wheels have a decisive impact on a car's handling, as they are the only parts that come into direct contact with the road surface and are also responsible for supporting the entire weight of the vehicle.

There are many reasons, both objective and subjective, that can cause wheel alignment to deviate from the manufacturer's specifications. After a period of use, the suspension and steering system linkages will wear down or become loose, especially if the vehicle frequently travels on rough terrain, hilly roads, gravel roads, etc. It could also be due to the driver frequently driving onto sidewalks at an angle, collisions, or overloading the vehicle.

Because wheel alignment errors occur gradually and don't have immediate consequences, most drivers are unaware of the problem. Some vehicles with misalignments are only slightly affected if the issue isn't detected early, but others only have noticeable consequences before the owner takes the vehicle for repair.

Failure to detect and correct these issues promptly can lead to several dangerous situations for both the vehicle and its occupants, such as uneven tire wear, wheel vibration, steering wheel veering to one side when driving straight, wheel misalignment, or even loss of control.

Whether a car offers a smooth, precise, and agile driving experience, or requires significant effort to steer, is greatly influenced by its wheel alignment angle. An optimal wheel alignment design not only ensures smoother and safer operation but also guarantees the durability of mechanical components. Therefore, in practical use and maintenance, car owners should maintain the original alignment by performing regular checks and adjustments as needed.

Toe alignment is the difference between the distance between the two tire sidewalls measured from the rear and the distance between the two tire sidewalls measured from the front on the same axle. Toe adjustment is the alignment of the two wheels on the same axle in the direction of travel. Toe alignment is zero when the two wheels are parallel. Toe-in (positive toe alignment) occurs when the distance between the two front tire sidewalls is shorter than the distance between the two rear tire sidewalls, while toe-out (negative toe alignment) is the opposite.

Both toe-in and toe-out affect the ride comfort of the vehicle, manifesting as vibration in the front of the car and steering wheel, steering instability, uneven tire wear, and often creating jagged wear patterns between the tire treads. In severe cases, it can even cause the tires to fail very quickly, a condition many people refer to as "tire wear": Excessive positive toe-in will wear down the outer side of the tire, while excessive negative toe-in will wear down the inner side of the tire.

Camber is the angle between the vertical axis of the steering wheel and the vertical axis of the vehicle when viewed from the front or rear. Camber is measured in degrees and minutes. Zero camber occurs when the wheel is perpendicular to the road surface, positive camber occurs when the wheel is tilted outwards, and negative camber occurs when the wheel is tilted inwards.

Whether the camber is positive or negative, it reduces the contact surface area between the wheel and the road, affecting grip, thereby reducing vehicle stability during operation, and causing uneven tire wear. If the tire wear is greater on the inner shoulder, it is due to negative camber.

Conversely, if the outer shoulder is more worn, it indicates positive camber. Additionally, this can cause the tire to be noisier, potentially causing discomfort for those inside the vehicle.

Caster is the angle between the vertical axis of the wheel and the steering column. A positive Caster means the wheel is in front of the vertical axis, and conversely, it is behind the axis in the direction of vehicle movement. Caster directly affects the steering speed and turning radius; a smaller Caster results in a lighter steering wheel travel. Overloading the vehicle, causing the springs to weaken or sag, will affect Caster. Additionally, ensuring the chassis is at its designed height is also important if you want to maintain proper Caster alignment.

A 0-caster wheel is when the steering axis is aligned vertically, a positive caster wheel is when the steering axis is tilted backward, and a negative caster wheel is when the steering axis is tilted forward. While an incorrect caster wheel doesn't cause tire wear, if one wheel has a more positive caster than the other, it will pull the wheel toward the center of the vehicle, causing the car to tend to veer toward the wheel with the less positive caster.

It's difficult to detect the effects of incorrect wheel alignment with the naked eye, and by the time consequences occur, it's often too late. Therefore, it's best to have your wheel alignment checked and adjusted at least once a year, or every 10,000 km, to prevent damage and extend the lifespan of your vehicle.

Furthermore, thanks to various types of high-tech machinery, the process of checking and adjusting wheel alignment is now more accurate and convenient than traditional techniques.