2012 X5 50i -- about to order, question on adaptive drive and wheel size! Help please

[MJim]

Originally Posted by barbja

I like the look of 20s too and am concerned about the ride. What I've decided to do is order with the 19s (unlike most, I hate 214 wheels and don't want the summer tires BMW ships on 20s), then switch out to some 20" 259s with Conti DWS or Toyo Proxes.

I'm hoping that the 20" + non-RFT will be a good combination. I do tend to take rough pavement and speed bumps pretty fast, so the 19s won't leave the stable until a good evaluation period is over.

If you want to take speed bumps fast, you probably want to make sure you have the non sports suspension. I tried on my test drive (sports suspension and 20s) naively thinking that a big 4x4 will float over, but felt like i'd taken it in the flintstones car!! I live in a part of London famous for it's p.i.t.a. speed bumps (Mr Clarksom even commented as such) so that clinched it for me!!

[ard]

Originally Posted by flyfisher

Would it also be accurate to say that adaptive drive would help to some extent with the ride quality aspect? Or is that hoping for too much?

Not at all. You are talking about entirely different aspects of handling.

Here is the thing- you need to look at a car's handling as a dynamic, mechanical frequency based system in which you have a large car that is attempting to 'adapt' between an input frequency (dictated by speed, terrain, direction changes and road surface irregularities).

Tire sidewall is THE primary damping and elastic element in the model between the tire patch and the first rigid element (the wheel). Changing suspension components past the wheel (ie springs, struts, adaptive drive) cannot alter the sidewall.

What happens with reduced side wall, simply, is that in rougg roads the wheel will bounce and not conform, this causes the contact patch to deform dynamically...in low traction conditions (ie rain, snow, very high speeds) the car will simply be less sure footed.


AD changes the overall body dynamics, (pitch and roll, settling in curves, etc) but will not change the 'ride' in terms of harshness.

[MRV99]

My 2011 has adpative drive and style 336(20") and I can attest that the car performs like a champ. I have owned 2 E70's and have had adaptive drive on both of them X5's (2007 w/ 211 19"). NOW, my X5 has been at the dealer for 39 or maybe 40 days now and after 30 days in a F10 535, I requested a X5 loaner and they were nice enough to give me a 5.0 with 214's and no adaptive drive. For just general cruzing, you don't need or use the adaptive drive because it will firm the ride up. But as soon as you start driving spirited, the adaptive drive really proves its price.

[ard]

Originally Posted by MRV99

you don't need or use the adaptive drive because it will firm the ride up. .

How do you turn adaptive drive off?

it is always on, only two different 'tuning settings'....