How does a car steering wheel automatically return to its center when accelerating after a turn?
In: Engineering
The front wheels’ steering axles are angled slightly. This results in the centripetal force of a turn (the feeling of being thrown sideways) pushing the wheels back towards center. Because the force depends on the speed of the vehicle, if you go backwards, it actually turns the wheel *away* from center.
Because of something called ‘castor angle’
Notice how in [this](https://thumbs.dreamstime.com/z/brakes-car-removed-wheel-109315615.jpg) picture the whole shock assembly is slightly tilted backwards?
If you imagine following the line that makes until it touches the ground, it’s going to be slightly *ahead* of the point where the tire itself (when it’s fitted) touches the ground.
What that means is the contact point of the car’s steering wheels is behind the point around which they rotate (when steering).
In other words, they’re arranged exactly the same way as the wheels on a shopping cart. The point they touch the ground is [behind the point around which they rotate](https://bigbasketco.com/wp-content/uploads/steel-wire-cart-25w-05.jpg).
What this does is literally drag the wheels into line with the movement of the car once you’re moving forward.
As another response has said, if you reverse, the wheel will want to spin around, not for the reason they’ve stated, exactly, but for exactly the same reason pulling a shopping backwards causes the wheels to spin round the other way.
The system is hydraulic. When you turn the wheel, you create pressure in the system. If you let the wheel go, the pressure wants to go away. This forces the everything back to center.
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