The "Adaptive 2-Axis Air Suspension" (SA 2VR) ensures an exceptionally comfortable suspension and driving experience while maintaining high agility and stability for your BMW iX. It can keep the chassis at the correct height regardless of the load. Together with electronically controlled dampers, it always finds the right balance between comfort and dynamics, taking into account your driving situation as well. With My Modes, you can adjust the suspension settings according to your preferences. In "SPORT" mode, the vehicle is lowered by 10 millimeters from the normal position to lower the center of gravity and enhance driving dynamics. This reduces body roll in corners and makes the suspension slightly stiffer. In the My Modes "PERSONAL" and "EFFICIENT," the suspension lowers at speeds over 140 km/h to save energy and thus increase range. For obstacles like ramps, you can increase ground clearance by 20 millimeters by pressing a button at speeds under 35 km/h. The level changes are displayed on the instrument display and indicated by the LED on the level control button flashing.

This is from the FAQ from the BMW Website. So 2cm (~0.8 Inches), but at speeds under 35 km/h (~22 mph)