For enhanced safety, the front and rear seat shoulder belts of the Volvo XC40 have pretensioners to tighten the seatbelts and eliminate dangerous slack in the event of a collision and force limiters to limit the pressure the belts will exert on the passengers. The BMW X4 doesn’t offer pretensioners for its rear seat belts.
For enhanced safety, the front seat shoulder belts of the Volvo XC40 are height-adjustable to accommodate a wide variety of driver and passenger heights. A better fit can prevent injuries and the increased comfort also encourages passengers to buckle up. The BMW X4 doesn’t offer height-adjustable seat belts.
Both the XC40 and X4 have child safety locks to prevent children from opening the rear doors. The XC40 has power child safety locks, allowing the driver to activate and deactivate them from the driver's seat and to know when they're engaged. The X4’s child locks have to be individually engaged at each rear door with a manual switch. The driver can’t know the status of the locks without opening the doors and checking them.
In the past twenty years hundreds of infants and young children have died after being left in vehicles, usually by accident. When turning the vehicle off, drivers of the XC40 are reminded to check the back seat if they opened the rear door before starting out. The X4 doesn’t offer a back seat reminder.
Both the XC40 and X4 have rear cross-traffic warning, but the XC40 has Braking Intervention (automatically applies the brakes) to better prevent a collision when backing near traffic. The X4’s Cross Traffic Warning doesn’t automatically brake.
Both the XC40 and the X4 have standard driver and passenger frontal airbags, front side-impact airbags, driver knee airbags, side-impact head airbags, plastic fuel tanks, 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, lane departure warning systems, blind spot warning systems, rearview cameras, rear cross-path warning, driver alert monitors and available around view monitors.
For its top level performance in all IIHS frontal, side, rear impact and roof-crush tests, and its standard front crash prevention system, the Insurance Institute for Highway Safety grants the XC40 the rating of “Top Safety Pick” for 2017, a rating granted to only 207 vehicles tested by the IIHS. The X4 has not been tested, yet.