The BMW X3 M has standard driver and front passenger side knee airbags mounted low on the dashboard. These airbags helps prevent the driver and front passenger from sliding under their seatbelts or the main frontal airbags; this keeps them better positioned during a collision for maximum protection. Knee airbags also help keep the legs from striking the dashboard, preventing knee and leg injuries in the case of a serious frontal collision. The AMG GLB doesn’t offer a front passenger side knee airbag.
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 AMG GLB doesn’t offer a whiplash protection system.
The X3 M has a standard PostCrash iBrake, which automatically applies the brakes in the event of a crash to help prevent secondary collisions and prevent further injuries. The AMG GLB doesn’t offer a post collision braking system: in the event of a collision that triggers the airbags, more collisions are possible without the protection of airbags that may have already deployed.
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 AMG GLB.
To help make backing out of a parking space safer, the X3 M’s standard rear cross-path warning system uses sensors in the rear bumper to alert the driver to vehicles approaching from the side, helping the driver avoid collisions. The AMG GLB doesn’t offer a cross-path warning system.
Both the X3 M and the AMG GLB have standard driver and passenger frontal airbags, front side-impact airbags, driver knee airbags, side-impact head airbags, front seatbelt pretensioners, four-wheel antilock brakes, all wheel drive, traction control, electronic stability systems to prevent skidding, crash mitigating brakes, daytime running lights, blind spot warning systems, rearview cameras, driver alert monitors and available around view monitors.
The BMW X3 M weighs 741 pounds more than the Mercedes AMG GLB. The NHTSA advises that heavier vehicles are much safer in collisions than their significantly lighter counterparts.
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, with its optional front crash prevention system, and its headlight’s “Good” rating, the Insurance Institute for Highway Safety grants the X3 M its highest rating: “Top Pick Plus” for 2019, a rating granted to only 113 vehicles tested by the IIHS. The AMG GLB has not been tested, yet.