Three angles, and most people know one
Alignment gets talked about as a single setting. It is three, they do different jobs, and knowing which is which explains why one vehicle wears tires and another pulls.
Toe is whether the wheels point slightly toward each other or away. It does more damage to tires than the other two together, because a wheel pointing even slightly off is being dragged sideways for every mile. Feathered tread, smooth one way and sharp the other across the face, is the classic sign.
Camber is how far the top of the wheel leans in or out. Wrong camber wears one edge of a tire and leaves the rest looking healthy.
Caster is the angle of the steering axis seen from the side. It does not wear tires much. What it affects is how the vehicle feels: whether the steering self-centers after a corner, whether it wanders, and whether it pulls to one side.
A vehicle with a wear problem and a vehicle with a handling problem are therefore usually telling you about different angles, which is why "it drives fine" is not evidence that the alignment is correct.
When to book it
The national alignment page lists the occasions. What the three angles add is a way to read your own symptom before you call: wear points at toe or camber, feel points at caster, and a vehicle showing both has more than one angle out.
The last one matters more than it looks. An alignment done after a new set is fitted means the new tires spent their first miles correcting the fault that destroyed the previous set. Say when you call if both are due, so the order is right.
What alignment cannot do
Fix worn components. A vehicle that will not hold an alignment has something underneath it moving under load. Suspension repair is offered at this store, so the sequence can run properly in one visit.
A vibration rather than a pull is balance instead.
About this store
The Boise store runs sixteen services, the longest list in Idaho, carries all nine Purcell tire categories, and is managed by Tyrel Perkins. It also aligns heavy trucks and trailers.
See the national car and light truck alignment page for all 40 locations.