There is the rear-wheel and all-wheel drive, but have you also heard of all-wheel steering? The rear wheels steer is just like the front wheels. But do you really know what all-wheel steering means and how it functions?
What is All-Wheel Steering?
All-wheel steering is when the driver can turn all four wheels when the steering wheel is turned in either direction. It might seem like a trivial feature to have, but there are good reasons for it. Here are a few advantages of this mechanism according to Oards.com:
- A smaller turning radius: A four-wheel steering system allows the vehicle to turn tighter in parking situations or in U-turns.
- More stability: Four-wheel steering allows for more control at higher speeds, making the vehicle easier to control.
- Better steering response: With all four wheels responding to your steering commands, a vehicle with four-wheel steering will feel much more responsive when the driver turns the wheel.
- Faster lane changes: When all four wheels are turning in the same direction, the vehicle will change lanes much quicker.
- More safety: A stable car is a safer car. Four-wheel steering can reduce a vehicle’s body roll, which could mean the difference between losing control going into a corner and getting into an accident or not.
Benefits of All-Wheel Steering
For all-wheel steering cars, like the Audi A8, the two rear wheels turn in the opposite direction in low-speed cornering and manoeuvres. When the rear wheels turn in against the steering direction, it allows for quicker turn-in and reduces the overall turning circle by about one meter.
This is known as “counter-phase” steering because the rear wheels turn in the opposite direction of the front wheels, providing a smaller turning radius and better agility. This would be especially helpful for bigger vehicles like vans or large cars like the Audi A8.
At higher speeds, typically over 30 to 40 mph, the rear wheels turn in the same direction as the front wheels. This is called “in-phase steering,” as all four wheels turn in the same direction at the same time.
The advantage of having all-wheel steering in a higher-speed situation is that the vehicle will be more stable, like when changing lanes, and lean less when going through a high-speed corner. When the vehicle is turning at high speed, and all four wheels are turning, both axles share the force applied to the vehicle as opposed to just the front axles.
Does All-Wheel Steering Have Disadvantages?
According to Oards.com, a four-wheel steering mechanism is typically constructed of electrical and mechanical components. If one part of it failed, then it would likely cause the whole mechanism to fail and, in turn, would take a long time to repair.
On top of repairing the system, the simple maintenance cost and initial buy-in are expensive. Manufacturing the parts needed for the system and the supply of replacement parts for later down the road cost a lot.
Is All-Wheel Steering Worth It?
Not exactly, which is why it’s mostly seen on high-end luxury or sports cars, you can find all-wheel steering on cars like the Acura RLX, Audi A6, A7, A8, a few different BMWs, a couple of Ferraris, and the Nissan R34 Skyline GT-R.
Conclusion
All-wheel steering is a feature that is nice to have, especially for high-speed driving or autocross-type courses; however, not having all-wheel steering in a car does not make a huge difference to your driving experience.
