Front wheel camber
When looking at the wheel from the front and rear direction, the tire is not installed vertically, but is slightly tilted and spread out in an "eight" shape, which is called negative camber. When it opens in the opposite direction, it is called positive camber. In the heyday of bias-ply tires, the camber angle was set relatively large because the tire was tilted to the ground to facilitate steering wheel operation. Nowadays, cars generally have camber angles set very small, close to vertical. Flat radial tires for automobiles are becoming more and more popular. Due to the characteristics of radial tires (tire pattern rigidity, wide outer tread), if a large camber angle is set, the tire will wear off and reduce tire friction. Also due to the continuous use of the power steering mechanism, the camber angle is also continuously reduced. Nonetheless, setting a slight camber angle can exert appropriate lateral thrust on the wheel bearings on the axle.
Toe-in of the front wheel
The toes should be pointed inward. The so-called "inward-shaped feet" means that the left and right front wheels are pointed inward respectively. The purpose of adopting this structure is to correct the outward rotation of the wheel caused by the above-mentioned front wheel camber angle. As mentioned earlier, steering wheel operation is made easy due to the camber. On the other hand, due to the tilt of the wheels, the left and right front wheels rotate outward respectively. In order to correct this problem, if the left and right wheels have an inward angle, the plus and minus are zero, and the left and right wheels can keep traveling in a straight line, reducing tire wear.
The above four positioning values ??are all indicators of front wheel positioning. The rear wheel alignment value is similar to the front wheel alignment value, but the rear wheel alignment of most cars is not adjustable.
If you are worried, you can go to a 4S store for a four-wheel alignment.