EPS (Electric) vs. HPS (Hydraulic) Power Steering

[93JC]

My car's steering is pretty good, I think. Low effort, no bump steer and good feedback. Like the RX-8 it's electro-hydraulic: hydraulic system with an electric pump. It seems to be a perfectly acceptable compromise to me.

I test drove a G5; the worst steering I've ever experienced. I would never buy one precisely because of the steering. It was so bad it was an absolute deal-breaker. It's purely electric, with the motor directly acting on the steering shaft. I don't have a ton of experience with other cars with purely electric steering but of the cars I know that have them (many Toyotas, e.g.) I have never heard a good thing about their steering.

[93JC]

I'd like to see a system where the EPS diminishes at higher speed. It wouldn't be hard to implement a sports car with a system with 100% EPS at 0-10 mph, then progressively fade until you have zero power steering at, say, 60 mph.

I drove a GTI with variable-assist electric power steering. It was okay except it didn't firm up soon enough. At parking lot speeds it was "pinky-finger light"; at 50 km/h it was still about the same...

[2o6]

Maybe It's because I drive them all the time now, but I don't see the fuss with the G5/Cobalt steering. It's light, but it feels about the same as any Toyota.

[MexicoCityM3]

I'd like to see a system where the EPS diminishes at higher speed. It wouldn't be hard to implement a sports car with a system with 100% EPS at 0-10 mph, then progressively fade until you have zero power steering at, say, 60 mph.

Both my cars do that and it's an option in any BMW afaik. An it is availabe both on EPS and HPS models.

[MX793]

Maybe It's because I drive them all the time now, but I don't see the fuss with the G5/Cobalt steering. It's light, but it feels about the same as any Toyota.

My gripe was less the steering effort and more the inconsistency of the steering effort.  And the tendency for the wheel to fight returning to center after taking a corner.  It was like there was a torsional damper in the wheel and it would start to return, then firm up and not want to return unless you steered it back to center.

[Raza]

Wife's G5 is numb at all speeds. You actually feel out of control sometimes in a high speed sweeper.

Well, it's a GM.  They had to do a lot of things wrong to get to where they are. 


Also, the Z4's steering is awesome.  Great weight and feel, great consistency. 

[S204STi]

Some EPS systems I've driven feel like crap, others are transparent.  Hydraulics aren't necessarily ideal, either.  Way more of it has to do with suspension geometry and programming than the choice of one over the other.  Or to phrase it differently, I've driven plenty of shitty hydraulic systems, and some poor EPS systems, so it's not fair to automatically write off EPS.

[hotrodalex]

From my experience, HPS has always been better. I haven't driven many of the cars w/ good EPS that you guys have listed, though.

My ideal car would be light enough that it wouldn't need PS.

[Laconian]

My car has some a speed-sensitive hydraulic rack. I prefer the manly man BMW electric steering.

[giant_mtb]

Correct me if I'm wrong, but I believe my car has EPS...I've never thought about it 'til now and just assumed it was HPS.  If that is the case, damn.  I never would have guessed.

[AutobahnSHO]

I really don't give a shit. I am taking the PS out of the MX-5 however.

I might go that route someday too.   Low HP plus when I'm in a 25-45mph corner I can feel it 'bouncing' back and forth against me.
My SHO did the same thing. Same design?

[Raza]

Correct me if I'm wrong, but I believe my car has EPS...I've never thought about it 'til now and just assumed it was HPS.  If that is the case, damn.  I never would have guessed.

I'm not sure if it's electric or hydraulic, but I think the steering in my brother's car is just okay.  The weighting is inconsistent.  It communicates just fine, but the effort it requires is unpredictable.  And the throttle is a little light, but not too light.  It's a fun car to drive, but it's not perfect. 

[S204STi]

My HPS, fwiw, has an issue at the moment regarding air getting into the system (no visible leaks, but apparently i need to replace a couple of clamps and remove an OEM o-ring), which leads to shudder in the column at low speeds.  EPS wouldn't have this issue with degrading hydraulic parts.

[VTEC_Inside]

FWIW, Honda has used methods of cutting back hydraulic assist at speed as far back as my '89 Accord. Re-running the damn lines up to that funny looking thing on the tranny confirmed this for me.

RSX is hydraulic, CSX is electric.

RSX is heavier, a little dead on center with these tires, but quite precise in a corner.

CSX is very light, precise in normal driving, but a bit dead when pushed. Thing is that the CSX moves around a lot when pushed hard where the RSX stays pretty flat. My biggest gripe is actually driving it in shitty weather. I could tell if I ran over a snowball in the Accord, in the CSX it becomes a video game minus force feedback.