Now should you get a two-wheel or four-wheel alignment? At any rate the technician will put a sensor on each wheel. In a two-wheel alignment rear toe and thrust angle is checked. Then all the adjustments are made on the front wheels. This happens on cars that don't have rear wheel adjustments, but can determine if there is something wrong with the back wheels.

In a four-wheel alignment the rear wheels are adjusted to specification before any front wheel adjustments are made. In relation to the added work, the four-wheel alignment does costs more. All vehicles should be 4-wheel aligned. Two-wheel alignments have become obsolete because they align only the front wheels to the vehicle's centerline. A 2-wheel alignment assumes the rear wheels are already aligned with the geometric centerline. Two-wheel alignments may save you a little money up front, but your vehicle's handling and tire tread life will be compromised.

Now, before any wheel alignment is done, the car should be road tested so the technician can see what the vehicle is doing. Then the front end should be thoroughly inspected for worn, bent or broken parts. He should check that the tires and wheels match and that the tires pressures are set correctly. (More)