[1 AKY]

Should/is the steering on a standard 318d M-Sport lighter than standard 330d M-Sport?

Reason I ask is that my brother's got a 318d as a courtesy car and I took it our for a spin. The steering on the 318d is so much lighter than mine. Is it to do with engine weight over the front wheels and tyre profile? or something else?

Aky

[willhollin]

If the 318d is an efficient dynamics model it may have the electric power steering option.

Yours will be hydraulic.

http://www.bmw.co.uk/bmwuk/efficient...ce=nationaltop

[MEGA]

Do they both have active steering?

[E92Fan]

Originally Posted by willhollin

If the 318d is an efficient dynamics model it may have the electric power steering option.

Yours will be hydraulic.

http://www.bmw.co.uk/bmwuk/efficient...ce=nationaltop

Both the 318d and 330d (since the ED revision) now use the electric steering system (EPS) as opposed to a conventional hydraulic rack. However, the 318d will have a smaller tyre footprint, and a lighter engine, so the steering will be lighter than the 330d. I am pretty sure the pre-ED 330d used a hydraulic steering rack, which is much heavier in weight than the electric system, but also has the advantage of being much more laden with feel and feedback (the electric systems are much less tactile in comparison).

[Porscha!]

What made them go over to electronic p/s?

[E92Fan]

Originally Posted by Porscha!

What made them go over to electronic p/s?

Efficiency - EPS is much much more efficient that the hydraulic system, which saps engine power when the steering wheel is turned even the tiniest amount. The EPS is also much lighter than a hydraulic system, and easier to package. In terms of servicing, it's also much quicker to do an alignment, as there's no need to ensure the steering wheel is 100% centralised - the wheel can simply be disconnected from the EPS and repositioned before being activated again. EPS is an essential part of the drive to make cars more economical, and lower CO2 emissions...

Downsides? Lack of feel, lack of feedback, and artificial weighting.

[Porscha!]

Originally Posted by E92Fan

Efficiency - EPS is much much more efficient that the hydraulic system, which saps engine power when the steering wheel is turned even the tiniest amount. The EPS is also much lighter than a hydraulic system, and easier to package. In terms of servicing, it's also much quicker to do an alignment, as there's no need to ensure the steering wheel is 100% centralised - the wheel can simply be disconnected from the EPS and repositioned before being activated again. EPS is an essential part of the drive to make cars more economical, and lower CO2 emissions...

Downsides? Lack of feel, lack of feedback, and artificial weighting.

Thanks

[doughboy]

Thankfully the 335i and 335d still have real hydraulic assistance, even post ED.

The larger engined cars are built to feel more 'weighty' to satisfy customer needs, If you bought a 330i and it rattled and bounced like a lightweight 318 you be miffed.

Even the doors seem heavier. the carpet thicker, the dash more solid - just more chunky all round.

[xenon]

Originally Posted by doughboy

Thankfully the 335i and 335d still have real hydraulic assistance, even post ED.

The others are "real hydraulic assistance", as you call it, and work just the same. The only difference is that the hydraulic pump is electric as opposed to being constantly driven by the engine. Therefore the electronics can shut off the pump in the 95% of time when it is unrequired.

That said, it is far too light but it is far too light on the 335D too.

[MEGA]

Yay for pre-Ed "real" hydraulics in my 320d

[E92Fan]

Originally Posted by MEGA

Yay for pre-Ed "real" hydraulics in my 320d

Ummm... nope sorry!!! You have the EPS system, not the "real" hydraulic system..

[doughboy]

Originally Posted by xenon

The others are "real hydraulic assistance", as you call it, and work just the same. The only difference is that the hydraulic pump is electric as opposed to being constantly driven by the engine.

OK for 'real hyrdraulic' read 'fully mechanical hydraulic'....

This 'only' difference, as you call it, is the major problem, you have to wait for the leccy pump to start, part of second yes, but you really feel it when doing a 3 point turn for example when you are steering quicker than the pump can cope. During periods of no-assist (i.e. straight ahead or low turning effort) the effect also dampens out forces coming back from the wheels to the steering wheel making it feel 'dead'

And then the car engineers get too clever with variable assistance, making it super light at low speeds when there is no need.

Why do you think M cars still have 'real hydraulic' systems (and non rft's for that matter)

Cos they can't make the EPS work in a way they see as 'desirable' for discerning buyers.

[xenon]

Originally Posted by doughboy

During periods of no-assist (i.e. straight ahead or low turning effort) the effect also dampens out forces coming back from the wheels to the steering wheel making it feel 'dead'

How so?

Whatever, all new cars are ridiculously over-assisted, including (in my humble opinion; I'm obviously not as discerning as you) the M3.

[doughboy]

Originally Posted by xenon

Howso?

Whatever, all new cars are ridiculously over-assisted, including (in my humble opinion; I'm obviously not as discerning as you) the M3.

Have you ever tried turning the steering (from the road wheels) on a jacked up car with PS when the engine is not running? Impossible, well the same applies to road forces 'trying' to turn the road wheels.


As for levels of assistance, it's only my opinion too, just like yours.

Cars aimed at people who appreciate mega assist and no feel will get that, and vice versa.

The 335i I test drove is not over assisted at all. Still nice and weighty, fairly hard work to palm the wheel round when parking but you can feel every bump and dip coming back through the wheel rim.

Not driven an M3 though, but I assumed that M division knew what they were talking about - maybe they should've come to you for advice

[xenon]

How does the 335i compare with your 330i? You will notice I said the 335d as I have not driven a 335i, but every BMW I have driven, including the M3, I feel are far too light. I understand there are technical reasons why the M3 does not have electric steering (but it soon will) and nothing to do with driver perceptions. If the 335i is fairly hard work to manouveur at parking speeds it must be vastly different to the 335d which, like the rest of the range, is too light.

[doughboy]

The E91 335i (assumed same as d) was very similar in feel to the my current 330i. i.e. markedly heavier than 'regular' cars I've used of late (mini, civic, 116i, 120d, 320d, 320i, focus, astra etc etc), most of which you can park with one finger.

The 330i just has an old school feel to it, without the arm-burn when parking on a non-assisted or early assisted car. When I get in it from my wifes civic, it feels like a non assisted car.

My experience is the EPS car only make it worse (by design I assume).

I had read the M3 was a little over assisted in EVO magazine, and they also said it was M divisions decision that the M3 and Z4M (and M5 / M6?) were mechanical because they were unable to get the feel they wanted from EPS systems (currently).

But environmental pressure will surely force them onto EPS too.....

Do you know why the 335i/d doesn't have EPS?

[xenon]

My car has the 19" 225M wheels (so quite a big contact patch) and feels over-assisted so the non M-Sport presumably feel lighter. The 944S2 is much better for steering feel and that's 18 years old...

[doughboy]

Originally Posted by xenon

My car has the 19" 225M wheels (so quite a big contact patch) and feels over-assisted so the non M-Sport presumably feel lighter. The 944S2 is much better for steering feel and that's 18 years old...

I was also talking about M sports with 225 wide 18" front tyres.

My 1990 309GTI with PS had the best steering i've ever used, simple things work best!