What Is 4-Wheel Steering?

The steering system lets you control where your car is going. There are many types, but one of the most prevalent and efficient types is the four-wheel steering system. If you’re planning to get a vehicle with 4-wheel steering, learning about the system can help you maximize its benefits.

What Is 4-Wheel Steering?

Four-wheel steering refers to a steering system that simultaneously turns both the front and rear wheels in response to your input on the steering wheel.

Many vehicles steer with either their front or rear pair of wheels. However, 4-wheel steering systems turn all four wheels at the same time.

Some people refer to 4-wheel steering as all-wheel steering. Others call it rear-wheel steering. However, unlike its front-wheel counterpart, 4-wheel steering turns both front and rear wheels.

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Pro Tip: A few GM four-wheel-drive pickups offer four-wheel steering as an option or feature. These include the GMC Sierra 1500 Denali, the Chevrolet Silverado, and the upcoming Chevrolet Silverado Electric.

Four-wheel steering on a four-wheel-drive pickup serves a different purpose than four-wheel steering on a passenger car built only for the highway.

On four-wheel-drive off-road vehicles, it’s for tighter turning radius. On four-wheel-drive pickups and SUVs, when the rear wheels turn opposite to the front wheels at low speeds, it reduces the wheelbase and the turning circle. This makes it easier to park, make U-turns, and navigate in narrow roads or off-road terrain.

But four-wheel steering also helps the vehicle retain stability on the highway when towing heavy loads even on a four-wheel-drive pickup or SUV and provides faster steering response.

How Does Four-Wheel Steering Work?

The 4-wheel steering system takes its cues from the steering wheel. When you rotate the steering wheel, actuators change the toe of the rear wheels, turning them even as the front wheels also turn.

Depending on your vehicle’s current speed, 4-wheel steering turns the rear wheels in the same direction as the front wheels or the opposite direction. By turning the rear wheels in the appropriate direction, the 4-wheel steering system improves the vehicle’s agility.

Car manufacturers usually come up with unique 4-wheel steering designs for proprietary use. However, almost all 4-wheel steering systems rely on actuators to adjust the toe of the rear wheels.

Some steering systems use old-fashioned hydraulic actuators. Other products feature electronic actuators with increased precision and responsiveness.

What Is Toe-in Four-Wheel Steering?

You’ve noticed “toe” appearing several times in the text. But what is it in the context of the 4-wheel steering system?

Toe is the angle that a wheel turns to or from the car. If the wheel points into the vehicle, the angle is called “toe in.” Toe in affects the stability of the car when driving at high speeds. Meanwhile, the term “toe out” gets used if the wheel turns out from the car, and affects agility when the vehicle drives slowly.

When you use toe in an automotive context, you usually refer to the angles of the front wheels. After all, many vehicles steered using those wheels.

However, you can also use toe to refer to the rear wheels’ angles in a 4-wheel steering system. After all, a vehicle with 4-wheel steering also uses its rear wheels to change direction.

Types of Four-Wheel Steering

Car manufacturers developed proprietary four-wheel steering for use in their vehicles. While they do the same thing, different four-wheel steering systems take different approaches to turning the front and rear wheels.

Examples of manufacturer-specific 4-wheel steering systems include the following:

• Acura: Precision All-Wheel Steer
• Audi: Dynamic All-Wheel Steering
• BMW: Integral Active Steering
• Cadillac: Active Rear Steering
• GMC: Crab Walk
• Lexus: Dynamic Rear-Wheel Steering

4-Wheel Steering Advantages

First introduced in 1988, 4-wheel steering took time to hit its stride. Nowadays, it’s one of the most popular options because of its many advantages over other types of steering systems.

More Responsive Steering

A 4-wheel steering system reacts faster when you turn the steering wheel. It also responds more precisely and gives you better control of your vehicle. Turning, cornering, and switching lanes become much easier when you drive a car with 4-wheel steering.

Better Stability While Cornering on Slippery Roads

Do you live or drive in a state that often gets precipitation like rain, snow, and hail? Bad weather renders the roads more slippery for ordinary tires, increasing the chances that your car might slide or slip, especially when making sharp turns at high speeds.

Fortunately, a car with 4-wheel steering handles slippery road surfaces better than most. It steers with all four wheels, reducing the chances of fishtailing when you rapidly complete a corner turn.

Smaller Turning Radius

Vehicles need enough room to complete a turn safely and smoothly. However, the road isn’t always open or roomy enough to accommodate maneuvers. And if that wasn’t bad enough, large vehicles take up more space.

Four-wheel steering resolves these issues by decreasing the vehicle’s turning radius at low speeds. When the rear wheels turn in the opposite direction that the front wheels face, the car can make smaller circular turns.

Increased Stability When Driving in a Straight Line

Not every road winds like a snake. Indeed, most roadways are usually straight, making them easier to use. However, straight roads can still catch you by surprise. High winds can buffet your vehicle without warning, and potholes are a constant concern on deteriorating roads and highways.

Fortunately, 4-wheel steering can also handle these challenges. It ensures the highest stability and minimizes swaying while driving into high winds and over uneven road surfaces. You can continue to enjoy a stable drive.

Changing Lanes Easier and Safer

Changing lanes can prove difficult, especially if you’re on a highway and many vehicles populate the road. Fortunately, a 4-wheel steering system makes this task easier. You don’t have to turn the steering wheel too much. Neither do you have to step on the gas too firmly to keep up your vehicle’s speed.

4-Wheel Steering Disadvantages

While the 4-wheel steering system offers many benefits over other types of steering, it also has several drawbacks. If you think the disadvantages outweigh the advantages, you might be better off sticking with more conventional steering systems.

The disadvantages of a 4-wheel steering system are the following:

High Price Tag

You get what you pay for. Four-wheel steering systems achieve their performance and safety at a commensurate price tag. Their capability and complexity drive their cost up, so they’re usually found in high-end vehicles.

Higher Complexity and Increased Maintenance

The typical 4-wheel steering system has various electronic components and parts that work together closely. If even a single cog of that finely tuned machine fails, the steering system grows less efficient.

Complex mechanisms like 4-wheel steering systems require more maintenance than simpler counterparts. They take more time to inspect and test for potential problems. Four-wheel steering also has a higher chance of developing an issue because it has so many parts that operate together.

Generally, 4-wheel steering advantages outweigh their disadvantages. If you can afford the initial price tag and meet the increased maintenance requirement, you’ll get a lot of mileage from a 4-wheel steering system.