Hydraulic steering vs electric?
Discussion
drdino said:
Better feel for the former, but EPAS tends to catch up nowadays.
Depends what you're looking for in steering. I think, steering 'feel' is irrelevant for 90% of car buyers today, so not surprising manufacturers are happy to go with EPS. For the other 10% which would likely include most people posting on here - it's tough s
t 
I didn't change my 135i for a M235 largely because of the awful EPS on the M235 compared with the proper hydraulic PAS on my 135i.
drdino said:
The latter is simpler,
Conventional hydraulic power assisted steering:rack,two pipes and a pump.
Electric system:
A decent power supply and usually a bigger alternator and associated wiring,relays etc.,an electric motor and associated gearing built onto a complex(in comparison)column,an ecu and various sensors it needs to make it all function correctly,
plus the added problem faced in positioning the motor with decent mountings,usually on the column where space is a premium.
EHPS system:
decent power supply and usually a bigger alternator and associated wiring,relays etc.,an electric motor and associated pump and reservoir,pipes,a rack,an ecu and the various sensors it needs to make it function correctly.
I see your point.
There are some decent EPAS systems, and some awful hydraulic systems. However, the way I see it; it's more difficult to get good feel out of EPAS than hydraulic, especially a "natural" feel.
It does seem to be a worrying trend that steering feel is slowly dying...comparing even a Mk1 Focus to a Mk3, the Mk1 steering is delightful.
It does seem to be a worrying trend that steering feel is slowly dying...comparing even a Mk1 Focus to a Mk3, the Mk1 steering is delightful.
As above - you never really know until you drive a car what its steering is like. The M135i apparently has hydraulic steering but I couldn't really tell much difference between it and the electric steering in my E90 in terms of feel. Whereas something like an RX-8 has electric steering but (what I would regard as) excellent steering feel.
How the hydraulic pressure is generated is irrelevant to how the steering is engineered and what feedback it provides. Electric PAS is taking over in smaller cars primarily because of packaging, the exact same reason people bh about the difficulty of changing headlight bulbs. There's only so much you can fit into a small engine bay, especially whilst leaving enough space to get the expected EuroNCAP scores.
h about the difficulty of changing headlight bulbs. There's only so much you can fit into a small engine bay, especially whilst leaving enough space to get the expected EuroNCAP scores.shoehorn said:
drdino said:
The latter is simpler,
Conventional hydraulic power assisted steering:rack,two pipes and a pump.
Electric system:
A decent power supply and usually a bigger alternator and associated wiring,relays etc.,an electric motor and associated gearing built onto a complex(in comparison)column,an ecu and various sensors it needs to make it all function correctly,
plus the added problem faced in positioning the motor with decent mountings,usually on the column where space is a premium.
EHPS system:
decent power supply and usually a bigger alternator and associated wiring,relays etc.,an electric motor and associated pump and reservoir,pipes,a rack,an ecu and the various sensors it needs to make it function correctly.
I see your point.
Rack:
Pump:
The two pipes: (this one has no cooling circuit which is unusual)
A motor bolted to the coumn does start to look like quite an attractive option now doesn't it
Frankthered said:
If you really want steering feel, surely you need to drive something without power steering??
Like most things there is a compromise, you tend to need more turns lock to lock in order to make low speed manoeuvring acceptable, this in turn will make the steering feel less 'sporty'. My 920kg kit car has a hydraulic rack which is not coupled up to give a faster ratio than the equivalent non-pas rack. The steering feel is great, but at less than 20mph you are reminded what pull-push steering is for.
Trif said:
itcaptainslow said:
comparing even a Mk1 Focus to a Mk3, the Mk1 steering is delightful.
Really? I was hugely disappointed by my Mk1 Focus in the steering department.I always fitted decent tyres which I find helps. Cheaper tyres tend to give a "glassy" feel in my experience.
buggalugs said:
You've undersold the complexity of the hydraulic system a little bit there.
Rack:
Pump:
The two pipes: (this one has no cooling circuit which is unusual)
A motor bolted to the coumn does start to look like quite an attractive option now doesn't it
Not in the slightest to me anyway - What I see above is a tried and tested system that worked perfectly and better IMO for the best part of 30years or more, and what I don't see are ECU's, another loom of wires, Relays and potentiometer's/sensors, water ingress causes problems that never existed in the older system and then there is the added draw on the alternator+battery which becomes all to apparent in cold weather, Rack:
Pump:
The two pipes: (this one has no cooling circuit which is unusual)
A motor bolted to the coumn does start to look like quite an attractive option now doesn't it
steering feel is not just performance based I find in low grip in a fwd its easier to feel the grip or lack of with PAS,
the aspect of Electric I think is useful is the lack of a full Column as in a crash they tend to do most damage to the driver, that and it can be packaged in a smaller area and easier which I would imagine is why a lot of manufacturer are leaning towards them
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