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Sedans Luxury Performance Sedans
10007 messages, Last post on Dec 01, 2009 at 7:40 AM
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Replying to: uglybear (Jan 06, 2007 11:49 am) |
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Replying to: uglybear (Jan 06, 2007 11:49 am) OK, if this is wrong and if your assertion is the proper case, wouldn't you think BMW would avoid using that name or if they did, they would have to give credit where credit is due? E.g., ESP is a Bosch product (but it was, according to the Mercedes fine print, developed in "cooperation" with Mercedes.) So, one configures a new BMW X3 and right there pops up Servotronic (not Audi Servotronic) as an optional extra -- $250. Configure a new 3 series and for $1275 you can opt for Active Steering. Ask the BMW dealer (and I did just an hour ago) what the difference is, and the first quip is, "about $1000." But seriously? No, they are not identical, Active Steering does two things, Servotronic does one, Active Steering effectively incorporates Servotronic (not an Audi or BMW invention apparently.) Here is what you gets when you checks the option box for Active Steering: Servotronic which is ROAD SPEED sensitive boost, the lower the road speed the higher the boost and vice versa, with Active Steering you also get ratio variability. As the car changes road speed the speed at which the wheel turns changes. At one speed a 1/4 turn of the steering wheel yields "X" turn of the road wheels, at a different speed, it may take 1/2 a turn of the steering wheel to generate "X" turn of the road wheels, at yet another speed, it may only take 1/8 a turn to generate "X" turn of the road wheels. Servotronic, according to the BMW sales guy is a HUGE improvement over non Servotronic set ups since it decreases boost as the road speed increases (the opposite of previous generations of "power steering" which generally remained linear or simply changed in step with engine RPM.) Our BMW rep says Active Steering is an acquired taste and that Servotronic over a non-Servotronic set up feels "just right" (to him, obviously.) Reading test reports of BMW models that were offered with OPTIONAL Servotronic, one can glean a message, Servotronic is a "wonderful" set up. Test reports praising the Servotronic steering can be found for the X3, X5 and M5. Other reports, less complimentary, can be found, too -- refering here to Active Steering. Maybe both set ups are an acquired taste. The praise for the new S8's implementation and last year's M5 Servotronic implementation can be googled with ease. Yet, if you do not drive back to back to back the same model with and without and then again with, you would be hard pressed to notice the boost differences, since the boost declines slowly as road speed rises. The effect, once you become aware of what it feels like both ways, is better highway response without a rise in effort at low speed or when stopped. BMW is moving all their vehicles to Active Steering. The interesting thing is, at this point, is that the code to special order Servotronic is one lower than the Active Steering option, making one wonder if the current price of Active Steering isn't the aspect that is over-boosted. The US Audi A6 comes standard with Servotronic and the software that controls it seems to be quite like the software that controls the BMW implementation of Servotronic. The Party Line: Speed-proportional variable ratio steering from ZF "The best steering feel is always at your fingertips, regardless of the conditions. ZF Servotronic steering incorporates speed-sensitivity to provide agile steering for easier manoeuvrability at low speed and greater feedback and stability at higher speeds." The full report: PowerSteering.com and I swear I did not make this up!
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Replying to: lexusguy (Jan 06, 2007 10:56 am) |
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Replying to: markcincinnati (Jan 06, 2007 2:05 pm) BMW Active Steering Don't confuse this with common variable-assist power steering, which merely makes the wheel feel lighter at slow speeds and firmer when going fast. The technology also links up with an electronic stability-control system for further advantage: If the car senses it's about to skid, an electric motor can automatically apply a subtle countersteer to stabilize the car. That's the difference: steering wheel still has meaty feeling, you just need to rotate it less. In A6 feel of the steering get lighter and ligher the slower you go. Sounds like standard variable assist to me.
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Replying to: uglybear (Jan 06, 2007 9:51 pm) Audi, BMW, Cadillac, LandRover, Volvo all use Servotronic, some applications (in some models) use Servotronic II. I think I would like Servotronic II, but several car magazines and our BMW salesrep seem to say it is an acquired taste. Some of the magazines have even called Active Steering maddening. Since it, at this point, isn't free, I would suggest to anyone that they first test cars with and without it. It is, apparently, more and more likely that Servotronic (one) is making its way into more and more models from many manufacturers. I would suspect if ActiveSteering or whatever ZF calls their version when it is marketed to a willing buyer catches on, we'll see ever lighter steering feel and very little steering wheel input needed (at slow speeds) to cause a large turn in. I do feel the road -- in this technology (Servotronic I) -- unlike the GM and Chryco products I grew up with in the 60's which had super boosted steering that felt like I wasn't turning a darn thing and any road feel was probably my imagination. I will keep digging, but "if" Servotronic II is the underlying technology for Active Steering, it certainly appears that it varies both the torque and the ratio based on road speed. Cadillac literature actually uses the Roman Numeral II after the word Servotronic to describe, essentially, what is Active Steering. One of the road tests of a BMW using this technology claimed ActiveSteering added "numbness" or subtracted road feel. Perhaps that is what you are commenting on? Going from a 2003 Audi to a 2005 Servotronic equipped BMW X3 then to another Servotronic equipped Audi, I enjoyed what I would characterize as "increased and improved responsiveness." Servotronic II seems (on paper) like it might be the best of all worlds -- unfortunately, at this time, the 530xi and the 3 series x's cannot be had with ActiveSteering, but the X3 can be had with Servotronic I and the X5 with ActiveSteering (with the sport package option.)  Audi, on the other hand, will offer sport suspension (and remember with a 530xi you cannot get a sport suspension, but you can get a sport package that changes the seats and wheels) and Servotronic on their AWD cars (DOH!) A 535xi with a sport suspension ought to be a fantastic car, perhaps an even better choice with THAT engine than the current V8's BMW offers. After having driven the 335i, I am a believer in the new turbos from BMW -- and I would, I suspect, want one with Servotronic I or Active Steering if such would be offered.
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Replying to: markcincinnati (Jan 06, 2007 10:28 am)
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Replying to: allagaroo (Jan 07, 2007 9:05 am) What acounts for the extra $150/month on the Audi over the M35? Interest rate (money factor) or sales price, or both?
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Replying to: markcincinnati (Jan 07, 2007 6:53 am) C&D absolutely hated it in their 645i test. They called it "the ultimate driving simulation".
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Replying to: lexusguy (Jan 07, 2007 10:06 am)
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Replying to: markcincinnati (Jan 07, 2007 1:14 pm) Oh I'm sure it will. Now that they pretty much all have electric steering, the "next big thing" seems to be variable ratio. That is except for Infiniti, who seem to be more interested in steering with the rear wheels. Nissan has been playing around with that for a very long time. |
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