If you’ve ever owned a car, you already know what a pain wheel alignment can cause. Sure, when you purchase a brand new vehicle, straight off the plant assembly lines, everything is peachy and all four wheels are perfectly aligned. As the car ages, the natural wear-and-tear of the vehicle perturbs the geometrical relationship between the four wheels and the vehicle, each other and the road. Why is alignment that important, though? Simple. Because when all four wheels are well aligned on all the three counts we mentioned above, the car will produce the least amount of resistance to the rolling speed, the least amount of friction and tire wear. Its traction capacities will also be maxed out. Now that we’ve defined wheel alignment, let us take a look at the three different types of angles that matter.
As any car service website will tell you, the most important type of wheel alignment angle is toe, because it directly affects tire wear. While researching alignment angles online, we came across the Prestige car service website, where we learned that toe represents the parallel lines between the wheels as viewed from above. The unit of measure for toe is inches or, alternatively, millimeters. Zero toe is achieved when the two front wheels are aimed ahead, while the distance between their leading edges is precisely the same one as the distance between the two trailing edges. However, it is worth noting that toe alignment never stays in perfect pitch while the car is being driven.
Look at your car from the front or the rear. If you notice that the wheels are tilting, either inward or outward, then your camber alignment angle is definitely askew. However, most often issues with the camber angle, which is measured in degrees, are not plainly noticeable with one’s naked eye. While the perfect tilt is zero, most vehicle setting will allow up to one degree of positive or negative camber. Whether the camber is positive or negative depends on the car’s suspension design. In a nutshell, if your camber settings are within half a degree side-to-side, then you’re safe. You want to avoid camber misalignments, as they will cause your tires to wear out unevenly on either one side. Camber applies to both sets of wheels (both those to the front, as well as those to the rear of your car).
The caster angle, which is also measured in degrees, represents the negative or positive tilt of the steering axis. It is only applicable to the front pair of wheels, as they are the only ones that steer—except, of course, for some more rare brands of Japanese cars which, in the past, came with four-wheel steering. You want your caster angle to be well aligned because, otherwise, you will have steering stability issues. Additionally, you may have to put in more of an effort while steering and your steering return will also be affected. While many choose to ignore this alignment angle, several European car brands have a lot of caster, in order to ensure that their vehicles still feel stable to drive, even at increased highway speeds.