Is Hydraulic Power Steering Actually Better Than Electric?
And how in all that’s good and decent does power steering even work? Our experts have the answer.
- Cars 101
- Guides & Gear
There is a war of hyperbolic statements among enthusiasts, waged both in the comment sections of websites and in the texts of articles. Not one of worldly significance or anything that’d affect our daily lives, but one revolving around the switch from hydraulically assisted to electrically assisted power steering. Yes, I’m being serious.
Go to a review of any new sports car, one that switched from hydraulic power steering to electric power steering, and you’ll find savage comments on the state of sports car manufacturing or how the ‘95 Mustang GT was the pinnacle of steering feel and everything that’s come out since is…[insert your favorite fecal expletive here].
This all flies in the face of the fact that the average consumer couldn’t care less about the car’s steering system. Looking in, this likely seems like a weird hill to die on, but it’s an argument that’s captivated most enthusiast communities. Especially when it comes to steering feel.
To catch you up about this pitfall-laden fight, The Drive’s undecided editors dropped our collective knowledge on power steering, steering feel, and how it all works below. Get ready for one pedantic issue.
What Is Power Steering?
Power steering simply implies that your car’s steering uses electricity or hydraulic pressure to augment the effort needed to steer the vehicle. This reduces the stress on the driver and allows for easier low-speed maneuverability.
How Does Power Steering Work?
The functionality of power steering comes down to magical wizardry. Joking! Let’s break it down.
Electric Power Steering
Though hydraulic power steering has been the favored system for many decades, it wasn’t the first. The first power steering system was implemented on a 5-ton truck in Columbia in 1876. Little is known about the inventor, whose surname was Fitts. The truck used an electric motor to assist the driver in turning the front wheels.
Today’s modern systems work much differently, and it starts with position and torque sensors that are affixed to both the steering column and steering gear. The car’s ECU then interprets signals sent by these sensors and applies specific parameters to the steering wheel and the drive wheels depending on certain conditions, variables, and situations.
Because electric power-assisted steering systems, or EPAS, are controlled electronically, varying degrees of resistance can be applied to the steering column. This allows for greater precision in both low and high-speed situations.
Hydraulic Power Steering
Hydraulic systems are slightly more complicated than EPAS due to additional mechanical parts and fluid. A hydraulic power steering system uses hydraulic fluid, a cylinder, a pump, and one or more control valves to multiply the force applied to a steering wheel via its inputs.
As stated, the steering wheel operates one or more control valves to allow the flow of the hydraulic fluid to the cylinder. The more torque to the steering wheel a driver inputs, the more fluid flows through the valves to the cylinder. The pump is normally driven by a belt connected to the vehicle's engine, which then pushes the hydraulic fluid through the cylinder to the steering gear. This then turns the wheels.
Most hydraulic pumps are positive-displacement, meaning the hydraulic fluid flow rates are equivalent to engine speed, low engine speed equals low-speed steering. A high engine speed equals high-speed steering. But because this would certainly mean you’d fly off the road when attempting a lane change, a flow-control valve sends a fraction of the pump's pressurized fluid back to the hydraulic reservoir when the engine is operating at higher speeds.
Are There Other Types of Steering Systems?
Electric and hydraulically-assisted steering aren’t the only types of steering systems in the world. Here are a few other examples.
Yah want gains, bruh? Then unassisted steering is the right one for you! Just kidding, well, sorta. Unassisted steering is exactly what it sounds like in that there’s no system helping take the load off the steering wheel. Cars without power steering are much more difficult to steer.
Electro-hydraulic steering is actually a blend of electric and hydraulic steering systems. Instead of traditional hydraulic steering, which is boosted using a pulley that turns off the engine, there’s an electric pump that pressurizes the hydraulic fluid in the steering system. The Gunther Werks 400R uses this type of system.
Steer-by-wire is the newest form of steering and is most commonly associated with future-forward EVs. In this case, the steering wheel isn’t actually connected to the wheels, unlike electric and hydraulic systems. Instead, the steering wheel and wheels talk to one another via the car’s onboard ECU and through a set of wires.
The upside is there are fewer mechanical parts to go wrong. The downside is that there aren’t any backup systems if something goes wrong. And because of that downside, no car on sale today features a fully steer-by-wire system—Infiniti's Direct Adaptive Steering is a partial steer-by-wire system.
Rear-wheel steering is a type of steering system connected to a hydraulic or electric power steering system that actuates not just the front wheels, but the rear wheels, too. These systems don’t adjust the angle of attack as severely as your front wheels, instead only operating with a few degrees of change. The R32-generation Nissan GT-R (called Super HICAS for "High Capacity Actively Controlled Steering"), along with all the subsequent GT-Rs, the old Honda Prelude, most new Porsche 911s, and even Bentley’s Flying Spur, all feature rear-wheel steering.
What Is Steering Feel?
Most consumers could not care less about steering feel, or the sensation of the road and your tires. All they care about is that it works when the time comes to evade an obstacle or switch lanes.
Enthusiasts, however, are chiefly aware of steering feel. They yearn to understand every corner’s slip point, the weight of the car leaning into a corner, the moment their tires break traction, the camber of a road’s apex, or its subtle flaws. It connects them to the road, the car, and the act of driving.
Instead of, you know, the steering wheel feeling like an inflatable tube man flapping around without a care in the world.
So Which Is Better, Electric or Hydraulic?
Ah, the question on everyone’s minds. Unfortunately, the answer isn’t as cut-and-dry as it once was. At least in the sense of steering feel.
If you’d have asked me 10 years ago, the answer was clearly hydraulic. The systems communicated the road, its imperfections, cambers, and what the tires were doing expertly. There was a sense of connection that was unrivaled by its electric power steering brethren, given that EPAS was in its infancy at the time and was...sensationless.
But times have changed and electric power steering is catching up to its fluid-based sibling. Cars like Porsche’s all-electric Taycan provide pinpoint accuracy and transmit those same attributes detailed above nearly as well as its hydraulic predecessors. As does the venerable Miata, which ditched hydraulically assisted steering for EPAS for the ND generation.
Are they perfect yet? No, but engineers are getting mightily close. What I’m saying is that those hydraulically assisted purists are fast becoming dinosaurs, relegated to Grandpa Simpson yelling at a cloud to get off his lawn.
FAQs About Power Steering
You’ve got questions, The Drive has answers!
Q: Is it dangerous to drive without power steering?
A: Let’s ask the Alfa Romeo 4C. Alfa?
A: Well, there’s your answer.
Q: What just happened?
A: You asked an Alfa Romeo, a car that comes from the factory without power steering, if it is dangerous to drive without power steering. You’re welcome.
Q: Uhhhh… Ok, then what are some signs of bad power steering?
A: You may hear groaning noises, whirring, screeching, really anything that sounds out of the ordinary is going to be a good indicator that something is wrong. Also, if your power steering suddenly becomes difficult to use, it may be broken.
Q: Can I drive without power steering fluid?
A: You can, as the Alfa shows, but it’ll be difficult to drive and turn. You may also do damage to the power steering cylinder and pump. Especially if you’re driving something big like an F-250 or Suburban.
Learn more about how car stereing works with this video from Engineering Explained.
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