Originally Posted by Cyberdemon
So the additional weight, drivetrain power loss, higher ride height, lower fuel economy, combined with the fact that in 95% of normal driving conditions the front wheels are doing nothing but sapping energy?
I test drove all 4 variations of the F30 (328i/xi, 335i/xi) and driving them back to back I could immediately notice the power robbery and extra weight of the x-Drive. It's the same difference you notice when driving with a car full of people.
For the 2013 328i and 328ix, from the BMW official page, the xDrive is 0.2" higher - 0.4%, not much at all.
The xDrive is 235 lbs heavier - but a load of people in my family weighs a lot more that that, I would account for 75% of it. More relevant is that the xDrive is FASTER, not slower - 5.7s to 60, rather than 5.8s to 60. Maybe you have the power robbery backwards?
I'm just curious, my xDrive is not here yet, but it is difficult to get a clear story here.
Maybe BMW knows the most - "That means under normal conditions, drive forces are spread out with a rear-wheel bias. But the moment the system senses excessive wheel slip, it subtly shifts torque to meet the changing conditions, offering maximum available traction and superior handling on all surfaces."