Understanding the meaning, importance of wheel alignment

Cars need a proper wheel alignment for a balanced ride, longer tire life, and improved mileage. But first, what is wheel alignment and why is it important? Wheel alignment technically means the adjustment of the suspension components holding the wheels, not the adjustment of the wheels/tires themselves. That said, there are a few easy ways to tell when your car has misaligned wheels. Keep in mind that this article focuses on the front wheels.

First, examine your tires to see if they have uneven wear on the tread. From there, observe these signs when driving: an off-center steering wheel direction when driving on a straight path, unusual steering wheel vibration, and the vehicle pulling over to one side. You should also keep an eye out for a sudden inefficiency in fuel economy. When you notice these signs, take your car to the nearest service shop and have it checked.

But before you do, it’s best to educate yourself with at least the basics of wheel alignment. That way, you’ll be able to promote service trust and avoid potential fraud. Here are some of the things to know and discuss with your professional mechanic.

This means the angle of the top and bottom edges of the wheel. If the top edge leans into the car body and the bottom is further out, that’s called a 'negative camber.' On the other hand, a “positive camber” is when the top edge is leaning out while the bottom edge is pointing in. Too much of both angles may speed up tire wear or give more stress on the suspension components. The ideal angle has to be straight from top to bottom. This evens out tire wear and decreases mechanical stress.

Do note that some carmakers these days put a slight bias on the negative camber by default. That’s to improve the car’s cornering grip and steering response. Read the vehicle’s Service Manual for this so the mechanic can adjust accordingly.

Toe refers to the turning angle of the wheel. If the wheel points into the car body, that’s called 'toe-in.' The opposite of that is referred to as 'toe-out.' That’s when the wheel points away from the body. Aside from premature tire wear, an incorrect toe angle may also cause the car to pull on either side of the road when driving straight.

When adjusting toe angles, the mechanic has to find a straight line between toe-in and toe-out. This is to preserve the tire and stabilize the car’s forward movement.

Caster refers to the leaning angle of the upper part of the suspension. The best way to understand this is to look at the car from the side. If the upper part leans more to the front bumper, that means the suspension has a 'negative caster.' On the other hand, a 'positive caster' is when it leans more toward the windshield or doors. Incorrect caster angles can cause the car to have unstable cornering. Moreover, the driver has to put more steering effort, and the tires would wear out faster.

As with the camber, the proper caster angle has to be straight down to improve cornering balance, allow the steering wheel to center on its own after cornering, and control tire wear.

While these 3 basic adjustments are commonly done on the front wheels, some cars nowadays require the same treatment on the rear wheels as well. So it’s ideal to consult on the vehicle’s Service Manual to fine-tune the adjustments.