There are three factors that go into wheel alignment; Toe, Camber and Caster.
When you feel the car pulling to one direction, or when your steering wheel is not centered, it is most often caused by toe.
On older cars camber, caster and rear toe are often non-adjustable. That leaves only front toe as the only adjustable parameter.
The most common at-home setups are strings, toe plates, or sometimes laser clamp systems.
What most people don’t know about are toe bars. They work in much the same principle as toe plates, but much more precise because of the rigidity of the setup.
If you’ve used toe plates, you’ll know just how frustrating it is to try to keep the toe plates up, flat and consistent.
The use of the toe bar is simple; you first measure the distance at the rear of the tires and then again at the front. The difference is your toe-in or your toe-out. Each line on the indicator is 1/16″.