2015 BMW M235i: Steering Sells BMWs

Edmunds.com

What's one of the most oft-used descriptions for BMW, Mercedes-Benz and Audi cars? Anecdotally, I'll say "solid." Or maybe "vault-like." You hear those little chestnuts all the time from us, the car-geek pressery. And while the car nerds take into account everything from chassis welds to spring rates to door thunk when describing German cars as "solid," I'm convinced that what sells Bimmers like our 2015 BMW M235i to most people is really the steering.

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ebeaudoin

Interesting to read. A certain enthusiast-focused car magazine has said that BMW's steering feel was thrown to the curb a few years ago. Specifically they griped that the EPS feels artificial and uncommunicative. Hmm.

hacefrio

@ebeaudoin: to be clear, I'm not comparing old hydraulic to new electric. I don't have enough experience pushing BMW's old hydro systems to the limits, so to me the differences between hydro and electric are incremental. Certainly more hardcore drivers/owners with multiple Bimmers on their resumes can articulate the differences (or claim they can), but for me, that thick road feel, that smaller amount of muscle you need to put into the wheel that isn't required in a Hyundai Sonata, for example, helps contribute to that sense of "solid" that I'm convinced helps sell these cars.

dlrodgers

kind of like the vinyl vs digital debate-electric steering box,while accurate and giving the right amount of feedback, does not have the
'feel' especially on initial turn in-but the days of hydraulic steering are in our rear view mirror-BMW and Porsche have the best electric racks

roadburner

Most drivers confuse steering effort with steering feel. I want the steering to tell me what is going on at the contact patches, and I have yet to drive a FXX BMW that has that ability.Even my wife's deadly dull 2009 E90 has more communicative steering- one of its very few saving graces..

mercedesfan

@dlrodgers,

I actually think BMW does EPS worst than most. Modern Bimmers have totally lifeless steering with artificial weighting. Even MB regularly does EPS better than BMW and few would argue that their racks are the stuff of legend. Porsche I definitely agree with, but I would also throw Cadillac in there. BMW only wishes they could tune EPS as well as Cadi.

roadburner

mercedesfan said:

@dlrodgers,

I actually think BMW does EPS worst than most. Modern Bimmers have totally lifeless steering with artificial weighting. Even MB regularly does EPS better than BMW and few would argue that their racks are the stuff of legend. Porsche I definitely agree with, but I would also throw Cadillac in there. BMW only wishes they could tune EPS as well as Cadi.

It pains me to say this, but as an active BMW CCA member who has owned nine Bimmers over the past 33 years, I agree 100%.

socal_eric

Talk to the major OEM suppliers of steering gear for companies like BMW which have been panned in recent years and you'll likely find an engineering team at the OEM who shrug their shoulders and state that it's due to the automaker's tuning requirements.

Having owned and driven quite a few cars with different types of steering gear, from hydraulically assisted recirculating ball steering boxes to conventional hydraulic rack and pinion setups to column and rack-mounted electrically assisted steering I'm not one to jump on the bandwagon against electric assist. You can have a great electrically assisted setup that's nicely weighted and provides great feedback and road feel.

For example, the '08-10 Cobalt SS Turbo is probably one of my favorite. The column-mounted electric assist has a touch of friction you can feel at parking lot speeds and likely wouldn't satisfy luxury car buyers looking for a couch on wheels but you can feel everything that's going on at the front wheels. Jim Hall was quoted in R&T as saying "Calling it one of the best handling front wheel drive cars ever doesn't do it justice - it's one of the best -handling cars, period."

Compare that to something like the Cadillac ATS. It has also generally been regarded as one of the better handling sedans in the entry level luxury class and uses rack-mounted electrical assist. It's a fun car to drive and handles well but isn't quite perfect in how the road feels through the steering wheel.

From a handling standpoint there are many factors such as tires, suspension bushings, how the rack is mounted to the chassis, steering column mounting, etc. in addition the rack and the assist method. Where GM faltered, and to their credit they aren't alone as BMW has similar complaints and uses the same rack in some of their models, they've all tried to tune the power steering controller to offer road feel and weight while filtering out impacts, kickback and other feedback that a regular driver might find unpleasant but an enthusiast would like.

There are also active steering correction algorithms available in newer power steering controllers that automakers can take advantage of to help with things like vehicle tracking over pavement imperfections and stability in heavy wind. Take the ATS again and while driving try wiggling the steering wheel left and right ever so slightly and you'll find an unpleasant feel and response as the rack is trying to compensate.

Every vehicle needs to be engineered as a complete solution. That means mechanically tuning the chassis along with electronic tuning. BMWs still handle well, some models better than others, but in my opinion where they've taken the biggest hit in the media is not from the chassis mechanical elements but instead trying to refine and filter the steering feedback through the electronic tuning.

For every enthusiast that cares about feeling every imperfection in the pavement through the rim of the steering wheel there are probably ten others that might find it unrefined in a high dollar luxury car. This disparity in expectations could be solved or at least reduced by offering truly driver selectable steering profiles, not just changes in assist effort. For some electrical steering controllers there doesn't appear to be much leeway in switching complete assist profiles but enabling that feature would allow automakers to tailor steering and handling to better match divergent needs of the drivers or driving conditions and not just make the steering feel heavy or light.

expensivehobby

The last loaner BMWs I had did not have the feel of our old X3 or 135i. Frankly, the X3, original body style, had great feel while the 135 i was solid to be sure but dominated in a way by the large tires. I still drive a friend's 2011 328 from time to time. The steering feels great but also the rock solid feeling of the car on the road at, say, 75-80 mph.
The more I hear, the more it seems like I really need to try out a new ATS or CTS .

roadburner

expensivehobby said:

The last loaner BMWs I had did not have the feel of our old X3 or 135i. Frankly, the X3, original body style, had great feel while the 135 i was solid to be sure but dominated in a way by the large tires. I still drive a friend's 2011 328 from time to time. The steering feels great but also the rock solid feeling of the car on the road at, say, 75-80 mph.
The more I hear, the more it seems like I really need to try out a new ATS or CTS .

Funny you should mention the X3; my wife and I both prefer the steering of my son's X3 to that of the E90.