Wheel
alignment is the position of the wheels relative to your car. When
properly aligned, the wheels point in the right direction. Without
proper alignment, the wheels resist your steering commands, as well
as each other. Alignment also affects gas mileage and tire wear. If
your tires are pointed in different directions, they fight against
each other and can cause tread wear.
Computerized alignment equipment is used to measure all
alignment angles on today's cars. These include both adjustable and
non-adjustable angles. (Non-adjustable angles require repair or
replacement of the suspension component.) The most common adjustable
angles are:
Toe This refers to the
tilted direction of the wheels toward or away from one another
when viewed from the top. Toe is the most critical tire
wearing angle. Tires that "toe-in" point toward one another.
Tires that "toe-out" point away from each other.
Camber This refers to the
tilt of the wheels toward or away from one another when viewed
from the front. Wheels that tilt in toward the vehicle have
"negative camber." Wheels that tilt away from the vehicle have
"positive camber."
Caster This refers to the
angle of the steering axis in relation to an imaginary
vertical line through the center of the wheel when viewed from
the side. "Positive caster" is the term used when the vertical
line is tilted back toward the rear. If it's tilted forward,
we call it "negative caster." The proper caster angle
stabilizes your car for better steering.
Thrust Angle This refers to the
relationship of all four wheels to each other, as well as
their relationship to an imaginary center line that runs from
bumper to bumper. The term "thrust line" refers to the
direction in which the rear wheels are pointed. Thrust angle
is correctable on cars with adjustable rear suspensions. If
your car has a non-adjustable suspension, thrust angle is
compensated for by aligning the front wheels to the rear
wheels.
