The X3 M’s pre-crash front seatbelts will tighten automatically in the event the vehicle detects an impending crash, improving protection against injury significantly. The Cayenne doesn’t offer pre-crash pretensioners.
The X3 M has standard Active Head Restraints, which use a specially designed headrest to protect the driver and front passenger from whiplash. During a rear-end collision, the Active Head Restraints system moves the headrests forward to prevent neck and spine injuries. The Cayenne doesn’t offer a whiplash protection system.
The X3 M’s standard lane departure warning system alerts a temporarily inattentive driver when the vehicle begins to leave its lane. A lane departure warning system costs extra on the Cayenne.
The X3 M has a standard blind spot warning system which uses sensors to alert the driver to objects in the vehicle’s blind spots where the side view mirrors don’t reveal them and moves the vehicle back into its lane. A system to reveal vehicles in the Cayenne’s blind spot costs extra.
To help make backing out of a parking space safer, the X3 M has a standard rear cross-path warning system, which uses sensors in the rear bumper to alert the driver to vehicles approaching from the side, helping the driver avoid collisions. Rear cross-path warning costs extra on the Cayenne.
The X3 M’s driver alert monitor detects an inattentive driver then sounds a warning and suggests a break. According to the NHTSA, drivers who fall asleep cause about 100,000 crashes and 1500 deaths a year. The Cayenne doesn’t offer a driver alert monitor.
Both the X3 M and the Cayenne have standard driver and passenger frontal airbags, front side-impact airbags, driver and front passenger knee airbags, side-impact head airbags, four-wheel antilock brakes, all wheel drive, traction control, electronic stability systems to prevent skidding, crash mitigating brakes, post-collision automatic braking systems, daytime running lights, rearview cameras and available around view monitors.
For its top level performance in IIHS driver and passenger-side small overlap frontal, moderate overlap frontal, side impact, roof strength and head restraint tests, its standard front crash prevention system, and its headlight’s “Good” rating, the Insurance Institute for Highway Safety grants the X3 M its highest rating: “Top Safety Pick Plus” for 2019, a rating granted to only 122 vehicles tested by the IIHS. The Cayenne has not been tested, yet.