Electric power steering (eps)

[Mark H]

I have been waiting for someone to start a threat on the pros and cons of such a unit and I haven't seen it yet so I thought I would start one.
Has anyone driven a car with EPS? does it feel different? Better? Worse?
Thanks
Mark

[fielderLS3]

The main pro is fuel economy due to elimination of the hydraulic pump. You'll also never have to top off the fluid every oil change like I do with my Alero.

The "feel" issue has more to do with how well engineered it is. I've had short drives in cars with this, including a 2004-2008 Malibu, a couple of Honda hybrids (I have a friend who is into those), and a 2010 Ford Fusion. My main experience with it is in my 2011 Mustang.

The Malibu and Honda systems felt really disconnected and sloppy (of course, that's a little expected given a rental spec car and hybrids). Ford seems to have the feel issue down a little better. The steering in my Mustang is better than any of the hydraulic systems on the GM cars I've driven, including the Camaro. However, it still isn't quite as good as my mother's 2005 Mustang, or my dad's Miata.

EPS allows the engineers to do some unusual stuff. Ford's system has software that automatically compensates for road crown and cross-winds. From my experience, this can be a two-edged sword. It's nice to be able to keep the car straight without having to pull on the wheel in those situations, but on relatively straight stretches of road, you can definitely feel the system adjusting and pulling the car one way or another, so that takes a little getting used to.

New Mustangs also have three electronic modes (Comfort, Sport, and Normal) that allows you to select and change the steering feel. My 2011 doesn't have that though (it's new for 2012), so I can't say what that feels like.

Pretty soon, most new cars will have this. I wouldn't worry about it though. Ford's is better than most conventional systems (though not quite as good as the very best hydraulic systems yet). I'm sure there are systems from other manufactures that do quite well also. Power steering had the same issues/worries when it first came out, but they got better quickly. It shouldn't take too long for engineers to work the bugs out of EPS as well.

(PS>>Sorry if I made this a Ford post. That is simply what I have the most experience with).

[Ron66Vette&10SS]

My wife's G6 has it. Feels just fine to me.

I think electric pwr steering is great.......more available power for the drive wheels

[VR Code R6P]

Most of the time, in my 2011 GT500, I do not notice anything different.

On one occasion, while turning the steering wheel quickly during parking, I thought I felt something a little different. I can't even explain it really.......just different.

[radz28]

My wifey's old '05 Jetta had it and it felt pretty good. I NEVER had a complaint. I believe it is more tunable via a electronic control module which can give better feel in slower speed and higher speed conditions. One less thing for the LSA to turn, so we get a little better power and mileage.

[Number 3]

It's down to an execution and tuning. Some cars lose on center feel. Others are very well done. Until recently, EPS was only used for lower HP applications. GM for example used EPS on 4 cylinder cars and HPS on V6.

[CamaroPilot]

Had it in my '05 Malibu. It didn't feel bad at all. It helped get the highway mpg to 36, even with the 200hp 3.5L v6.

[scritchy]

A friend has Electric Power Steering in his Fusion. He says there is absolutely no road feel at all and steering feels dead. He doesn't like it.

[MG]

Maybe a good thing would be not having to worry about frying the pump while doing some serious donuts?

[fielderLS3]

Originally Posted by MG

Maybe a good thing would be not having to worry about frying the pump while doing some serious donuts?

Not necessarily. The owner's manual for my 2011 Mustang warns that in situations where there is an unusually high or prolonged load on the power steering, the system will partially shut itself down temporarily to keep from overheating, making steering more difficult. This would probably be a rare occurrence, though.

[Mr. Wyndham]

Originally Posted by Number 3

It's down to an execution and tuning. Some cars lose on center feel. Others are very well done. Until recently, EPS was only used for lower HP applications. GM for example used EPS on 4 cylinder cars and HPS on V6.

My Cobalt has it and I LOVVVVEEEE IT.

Obviously, fuel economy is a benefit...but when you're just sitting in the driveway, it's tuned to make the steering wheel easy enough to turn with your pinky finger...helping to park. And the overall feel is...just more refined than the mechanically-feeling power steering, IMO....sort of like electronic throttle versus cable-actuated.

I'm happy to hear they're using this on the ZL1, and hopefully the technology carries over to other Camaro models. It's really a win-win-win, imo...

Originally Posted by fielderLS3

Not necessarily. The owner's manual for my 2011 Mustang warns that in situations where there is an unusually high or prolonged load on the power steering, the system will partially shut itself down temporarily to keep from overheating, making steering more difficult. This would probably be a rare occurrence, though.

For sure -- it's an electric motor there....so what happens when a motor can't spin but you're still powering it?

[DGthe3]

Originally Posted by Dragoneye

For sure -- it's an electric motor there....so what happens when a motor can't spin but you're still powering it?

Its my understanding that EPS is essentially just an electric pump instead of a mechanically driven pump. So it should always be able to spin unless the power steering fluid manages to somehow freeze ... in which case, you might have more severe problems to deal with.

[Number 3]

Originally Posted by DGthe3

Its my understanding that EPS is essentially just an electric pump instead of a mechanically driven pump. So it should always be able to spin unless the power steering fluid manages to somehow freeze ... in which case, you might have more severe problems to deal with.

Not quite.

There are really two types of EPS.

Column Mounted

http://nexteer.com/column_assist.html

And Rack Mounted

http://nexteer.com/rack_assist.html

Both use electric motors to drive either steering column or rack. This is why they are more difficult to set up. It's not just a hydraulic rack with fluid being pumped electrically. What you are thinking of is Electro-Hydraulic.

But to rip off a good description:

An electric motor is connected to a steering column or a manual rack. A sensor reads the X-Y coordinates and degree of rotation as the steering wheel is turned by the driver. The data from the sensor and an additional torque detector on the steering shaft are computed by the electric power steering control module. The amount of power from the steering assistance provided by the electric power steering system is computed from these and other variables (including speed of travel and traction [stability control system]). A control module directs the rotation degree of the motor at the same time the motor sensor communicates with the control module. These components work together to sustain a monitoring system for the electric power steering operation.

[chewy8]

i am glad its going to be on the zl1

[OldScoolCamaro]

Originally Posted by scritchy

A friend has Electric Power Steering in his Fusion. He says there is absolutely no road feel at all and steering feels dead. He doesn't like it.

I think you will find the reason for that lack of quality is because the one your friend has is made by Ford...ok seriously now, ...if the GM unit to be used in the new ZL1 is anything like the VW units I am confident there will be no complaints at all. They are smooth, precise, quick, and turn with little physical effort. There are no dead spots, lag, or sloppy sensations to any performance or road conditions. They are an upgrade over their predecessors by a noticeable margin. I can only speak for the VW ones now keep in mind.

[DGthe3]

Originally Posted by Number 3

Not quite.

There are really two types of EPS.

Column Mounted

http://nexteer.com/column_assist.html

And Rack Mounted

http://nexteer.com/rack_assist.html

Both use electric motors to drive either steering column or rack. This is why they are more difficult to set up. It's not just a hydraulic rack with fluid being pumped electrically. What you are thinking of is Electro-Hydraulic.

But to rip off a good description:

An electric motor is connected to a steering column or a manual rack. A sensor reads the X-Y coordinates and degree of rotation as the steering wheel is turned by the driver. The data from the sensor and an additional torque detector on the steering shaft are computed by the electric power steering control module. The amount of power from the steering assistance provided by the electric power steering system is computed from these and other variables (including speed of travel and traction [stability control system]). A control module directs the rotation degree of the motor at the same time the motor sensor communicates with the control module. These components work together to sustain a monitoring system for the electric power steering operation.

hmmm ... thanks

oh, and I (think) I fixed your 2nd link. It used to go to the same page as the first. Seems like it should go to the page you want now.