[Anterialis]

Hello!
After testing the car briefly on slippery roads in Norway where I live, I couldn't stop being a bit annoyed with the rear wheel only bias I feel the IX has. Maybe I'm wrong, but coming from the G05 which I currently own and love (which IMO has a perfect power balance rear to front) I definitely feel that I get an immediate wheel spin on the rear tires only, and then half a second or so later power from the front wheels. This results in the car's power dropping to near zero immediately after (rear) wheel spin for half a second or so until the front motor engages.

1) How does the x drive system work in this car?
2) I suspect the car drives with only the rear wheel motor engaged, and activates the front motor
Only when needed (power, loss of traction at rear wheels). Is this correct? Is there a way to override this behavior?

For the most part this behavior is understandable in my opinion as it saves battery. But when standing at the side of a slippery road waiting for a pocket between cars to enter, I often want maximum traction (immediate 4x4) to be able to safely enter the road. The way it works now is that the car stutters, waits for a second, then accelerates. It annoys me..

Also, sometimes driving on icy roads, I don't want the rear wheels lose traction first, I want the whole car (all wheels) to lose traction at the same time as this behavior is safer (avoids twisting around vertical axis) IMO.

Thanks

[nosnoop]

Originally Posted by Anterialis

Hello!
This results in the car's power dropping to near zero immediately after (rear) wheel spin for half a second or so until the front motor engages.

What you were experiencing was the traction control or the stability control at work. It cuts power from the motor when it senses wheel spin.

The X-Drive itself should work very fast, it uses "near-actuator wheel slip limitation technology" and it is much faster than older system.

Also, sometimes driving on icy roads, I don't want the rear wheels lose traction first, I want the whole car (all wheels) to lose traction at the same time as this behavior is safer (avoids twisting around vertical axis) IMO.

It will not.

But if you don't want traction control (cutting power), you can try turning DSC OFF - as long as you understand the downside of having DSC OFF.

[Rickardg]

Hi Anteralis,
Im a bit suprised about your experience since my feeling is the opposite. I belive it reacts extremely quick both the front - rear power distrubution and the DSC aswell.
I had your statements in mind this morning when i drove to work on snowy and icy roads but i could not provoke the behaivior you describe. Power distrubution was instant without any delay or lag at all, Could it have been anything wrong with the car you drove?

[Anterialis]

Thank you for the replies! This is encouraging, I only tested the car for an hour so this could be a result of a very specific situation, or an old software/firmware version (demo car).

Regarding the engine cutting power when detecting a wheel spin:
I agree that this is normal behavior, but if the wheel slip is happening to the rear wheel(s) only, the motor to the front wheels - where there is traction - should not stop. If both motors were active, the car's forward movement wouldn't stop as I understand it, as the front wheels would still move the vehicle forward without wheel slip. But, as the rear motor was the only motor active, the car "stopped" until the front motor activated. And this is the latency I believe I felt. It was at least 0,5s, maybe 1s as I remember it. Also the slip felt just like wheel slip from a RWD car (very quickly, twisting motion in car if happening in a turn, sudden drop in acceleration), which is very different from how it feels in a AWD (all wheels pulling simultaneously and one wheel slipping) car.

Also, the car did behave exactly like the I3 (and any other RWD cars) I once owned behaved; when I tried making the car spin while in a turn, the back end came out before the rear motor torque dropped immediately. It was again a brief latency (0,5 - 1s?) until the car started moving again as the front motor engaged.

My point is that if both motors (rear and front) were engaged and provided equal torque (50/50, or maybe 60/40 as it would be a better/typical bmw "feel"), the car would not lose traction as quickly. This IMO would be safer as it leaves the driver with a bigger safety zone (more total torque can be applied before a wheel starts to spin, front or back).

Are there any other IX owners who have noticed a similar behaviour? I am going to buy this car once my current G05 lease expires and this is still something I will learn to live with. But I am curious whether this "rear motor only" driving style can be overridden, e.g. in sport mode??