Few Facts on Four-Wheel Steering Explained

The intention of driving vehicles to turn way better by using all four-wheel steering has been an inspiration for car engineers for decades. In fact, back during the II World War era, United States Army thought of experimenting with AWD steering jeeps for aiding the firefighters to avail better maneuverability of rear steering drivetrain. Even in recent generations renowned automotive brands like Audi, BMW, Lexus, Porsche, Lamborghini, Ferrari, and Mercedes added AWD drivetrains to their vehicles.

The distribution of power in all four wheels of the vehicle not only benefitted in maintaining a good steering response but rather ensured better response and cornering stability while driving on icy or wet roads. Above that, we all know how cruel the American and Canadian winters are! They’re pretty brutal when it comes to driving on snow. The slightest loss of steering control can lead to potential accidents! 

Simple Explanation of 4-Wheel Steering Mechanism

The 4-wheel drive mechanism works quite differently from the conventional drivetrains. While the vehicle is at low speed, the rear wheels turn in a direction opposite to the front wheels turning direction. Whereas, when the vehicle is at a higher speed, the rear wheels turn in the same turning direction as the front wheels. 

This mechanism is known as ‘in-phase steering’ which allows the vehicle to maintain stability during high-speed corning. In in-phase steering, the vehicle usually leans less in and out of a corner because both axles share the same turning forces instead of providing more turning force to the front wheels only. Whereas, in counter-phase steering, the rear wheels turn at an angle slightly opposite from the turning angle of the front wheels. The main purpose of the counter-phase steering movement is to allow the vehicle to maintain a smaller turning radius so that better agility can be maintained whenever all 4 wheels steer. 

Types of Drivetrain: Briefly Explained 

Before moving into the discussion on why a four-wheel drivetrain is much more appreciated than the other types of drivetrain, it is important to know a bit about the different types of drivetrain too. There are four types of drivetrains, each of them briefly discussed below-

• (Front Wheel Drive) FWD - In an FWD system, the drivetrain components power up the front wheels to increase the traction in the front wheels. 

Few cars with FWD steering: Volkswagen Golf GTI, Audi A3, Volvo S60

• (Rear Wheel Drive) RWD - In an RWD system, power is transferred to the rear wheels that need maximum traction, especially when the vehicle is stuffed with heavy loads. The RWD drivetrain is also provided in performance cars for optimizing car handling

Few Cars with RWD steering: Nissan 370Z, Ford Mustang, and Mazda MX-5 Miata

• (4 Wheel Drive) 4WD- The4WD system is given to the vehicles for delivering maximum power to all four wheels. This kind of drivetrain comes with two driveshafts and a transfer case to provide power on all 4 wheels. Nowadays, some 4WD drivetrains come with the option to switch the power either to the 2 wheels or in all 4 wheels of the vehicle, depending upon the requirement. 

Few Cars with 4WD steering: Honda Prelude, Acura RLX, Acura TLX

• (All Wheel Drive) AWD - Although both AWD and the 4WD system deliver power to all the 4-wheels of a car, however, there’s a slight difference between them. While 4WD provides unconditional power to all the 4-wheels, the AWD system works with a sensor that determines and transfers power to the required wheels whenever needed. 

Few Cars with AWD steering- Ferrari, Mercedes Benz, Lexus

Benefits and Advantages of 4-Wheel Steering 

The 4-wheel steering technology is used for increasing the vehicle’s steering response time and enables a vehicle to maintain stability at higher speeds. A number of times, loss of steering control often leads to catastrophic accidents too. With the Four-wheel steering technology, it is easier to maintain unprecedented control and maneuverability on all four wheels instead of controlling only the 2 wheels of the car. Let’s take a closer look into the advantages of 4-wheel steering technology:

Steering response is better and quicker- Four-wheel steering always responds fairly faster than any other type of steering option. With better controllable steering it is easier for a driver to maneuver the car’s wheels to maintain distance from fellow drivers or pedestrians when they are close by. 

Easy to tackle the twisties - Often there are chances of encountering road accidents while driving through challenging roads when it is either wet or covered with slippery ice. A four-wheel steering mechanism enables a driver to turn the car from a corner without losing stability and control.

A preferred choice for tougher terrains-The winter seasons can be too treacherous, especially while driving over snow. A four-wheel steering mechanism is an added leverage to drive through such road conditions with minimum discomfort. The 4WD drivetrain can easily regain control over the tires if it is stuck in snow or hit the ice while driving upon it. 

Better stability while driving- Four-wheel steering enables a driver to maintain stability while driving on straight roads. The configurations of the steering help a driver to evade potholes while driving on a straight road and minimize the chances of swaying the vehicle at high winds. 

Lane changing turns easier- Four-wheel steering always ensures uniformity in the wheel movement, especially when the car is at high speed. All the wheels steer in the same direction as the front wheel resulting in better stability. Eventually, that makes lane changing easier while cruising on the highways.

Disadvantages of 4-Wheel Drive Steering

Although, 4-wheel drive steering technology has proved to be way better for steering the wheels with uniformity, however, it has certain disadvantages too. Some of the cons associated with 4-Wheel steering technology have been shared below:

Slightest malfunction can be risky - One of the biggest disadvantages of 4WD steering is it has a potential risk of malfunction. This system has multiple electronic components that synchronize with one another to respond whenever the steering wheel is moved by the driver toward any specific direction. A minute technical malfunction due to poor maintenance can damage the whole system, creating a ruckus within the entire mechanism.

Maintenance cost is higher- The 4-wheel drive steering mechanism requires more components and calibration than the other conventional steering systems, which is a costly deal indeed. Cars like Audi, Ferrari, and Cadillac have 4WD drivetrains which are fairly costlier than vehicles with conventional powertrains. 

Not a fuel-efficient choice- Low EPA mileage is one of the major disadvantages of vehicles with a 4-wheel steering mechanism. Since the drivetrain powers up all 4 wheels, depending upon the steering movement, the required fuel consumption is more for the vehicles equipped with one such drivetrain. 

Repair work can be a time-consuming affair- Usually, a number of electrical components are connected with a 4-wheel steering mechanism. It consists of an ECU and sensors that signal to switch power distribution from one wheel to another as per the requirement and other crucial components. When any of these parts malfunction, the whole mechanism gets compromised. To replace the entire drivetrain the daily use car has to spend sufficient time at the workshop or at the dealership.

Popular Types of 4-Wheel Steering Technology 

There are different types of 4-wheel steering options available in the market, although their functions are similar. Some of those options are shared below:

• Nissan’s High Capacity Actively Controlled Steering (HICAS)

• Audi’s Dynamic All-Wheel Steering System

• Porsche’s Rear-Axle Steering 

• Ferrari and Cadillac’s Active Kinematics Control (AKC) system