Gadgetory

in the beginning there was only one kind of steering you want to move the car a different direction you grabbed the steering wheel and put your shoulder into it power steering was either unheard of or very elite during a heavy vehicle by manual effort only emphasized the need for a steering assist we huffed and he even sweated behind the wheel until the first mainstream car with power steering hit showrooms the 1951 Chrysler Imperial was something that they called Hydra guy and then for 50 years power steering didn't really change a lot hydraulic was hydraulic like on this 67 cougar you basically have your steering rack that is very classic in just about every car of the era but to help you move that you've got this power Ram right up here this piece is nothing more than a hydraulic ram that pushes one way or the other to get your wheels to move which way you want it is told how much and what direction by this control valve up here and all this connects to your steering column where does it get all the pressure is what's interesting if you look up in there you see that pump that's the power steering pump run by a belt off the front of the engine that's where the big problems of these systems it's constantly putting drag on the engine creating a bunch of pressure even if you're not using it to steer that's called a parasitic loss that can set mpg in power but these days power steering has changed dramatically welcome to the era of epass electric power assisted steering now underneath this 2014 Jeep Cherokee a decidedly modern vehicle we find a very different steering system and electric power steering is here if you look up in this vicinity you're going to see the electric motor which is sitting on the steering rack those arms and linkages that move the wheels left and right another model is to take that motor and move it further up and put it on the actual steering column kind of heading up toward the firewall the effect is the same the electric motor and its electronics sense your effort on the wheel and add their own in kind and of course the same direction the efficiency the compactness the cleanliness and the accuracy of this system versus hydraulic is the big idea note there are also hybrid systems that remain hydraulic but replace the belt driven pump with an electric one the bigger trend however is to go fully electric okay so as you picked up on their four major benefits to electric power steering let's run them down first off is efficiency ZF which makes a lot of electric power steering system says they can save 90% of the energy that is parasitically wasted by hydraulic system put another way Chevy says their 2013 Malibu it's two and a half percent better mpg solely because it has electric power steering they've all parked out at 120 gallons of gas or about 500 bucks saved across ten years of ownership next up is addressability because it's an electric component it can be harnessed to the vehicles control systems to automate things like automatic parking assistance lane departure correction all kinds of things that are nudging into the area of autonomous driving it can also be used in the background for cornering improvement in cornering control now we have accuracy because it's driven largely by software changing its behavior and keeping it accurate with a feedback loop that a computer can monitor is quite easy that's not the case with hydraulic systems we want to change their behavior you largely have to go engineer new physical components for them and then there's compactness a big deal with automotive packaging designers instead of having a pump and belts and valves and a power ram you just have an electric motor and some wires going to and from it that allows a lot of space to be freed up and for things to be kept very compact and very cool in the engine bay so it's a win-win-win-win then why do so many driving purists kind of push back on electric power steering well part of it is because it's not what we've always had it's not hydraulic and let's face it we've all gotten used to hydraulic steering and automakers of dial it in quite nicely and early electric power steering systems did have some numbness to them and some poor what's called on centre feel that's been largely corrected in my experience I have a very hard time telling a good electric system from a refined hydraulic system until I look under the hood the future when electric power steering like we've seen today becomes steer-by-wire electric power steering that means the steering wheel basically becomes a game controller and has no mechanical connection to the front end at all that's down the road a few years and that's a separate car set 101