If it is a front-wheel drive vehicle, the double wishbone suspension assembled on the front wheel is equipped with steering mechanism besides the transmission mechanism between the upper and lower control arms, which makes its structure much more complicated than that without steering mechanism on the rear wheel. In the steering mechanism, the steering kingpin is determined by the connection position and angle between the steering wheel and the upper and lower control arms, and the steering wheel can rotate around the kingpin and jump up and down with the lower control arm. In the double wishbone suspension, the ball joint is usually used to meet the movement needs of the front wheel: the joint between the upper and lower control arms and the steering kingpin should not only support the front wheel to realize steering, but also control the up and down jitter of the wheel. However, due to the length difference between the upper and lower control arms, the design of double wishbone suspension is also put forward a severe test. If the length difference between the upper and lower control arms is too small, the left and right wheel gaps will be too large when the wheels shake, which will accelerate the external wear of the tires. On the other hand, if the length difference between the upper and lower arms is too large, the camber angle will be too large when the wheel turns, which will accelerate the wear of the inner side of the tire. Therefore, by increasing the length of the upper and lower control arms, the variation of the wheel track can be reduced and the variation of the camber angle can be controlled.
In addition, the upper and lower control arms of the double wishbone suspension can offset the lateral force, so that the strut shock absorber can no longer bear the lateral force, but only deal with the up and down jitter of the wheel, so it has good directional stability in corners. Known as the "King of Curves", mazda 6's front suspension adopts double wishbone suspension. Therefore, when mazda 6 is driving in a corner, the roll is small, and the overall feeling of the car body is well maintained.