For enhanced safety, the front seat shoulder belts of the Volvo S90 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 i4 doesn’t offer height-adjustable seat belts.
Both the S90 and i4 have child safety locks to prevent children from opening the rear doors. The S90 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 i4’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.
The Volvo S90 offers optional built in child booster seats. They’re more crash worthy than an added child seat because of their direct attachment to the seat. BMW doesn’t offer the convenience and security of a built-in child booster seat in the i4. Their owners must carry a heavy booster seat in and out of the vehicle; S90 owners can just fold their built-in child seat up or down.
The S90 has a standard Whiplash Protection System (WHIPS), which use a specially designed headrest to protect the driver and front passenger from whiplash. During a rear-end collision, the WHIPS moves the headrests forward to prevent neck and spine injuries. At the same time the pretensioning seatbelts fire, removing slack from the belts. The i4 doesn’t offer a whiplash protection system.
To provide maximum traction and stability on all roads, All-Wheel Drive is standard on the S90. But it costs extra on the i4.
Both the S90 and i4 have rear cross-traffic warning, but the S90 has Braking Intervention (automatically applies the brakes) to better prevent a collision when backing near traffic. The i4’s Cross Traffic Warning doesn’t automatically brake.
Both the S90 and the i4 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, 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 and driver alert 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 vehicle-to-vehicle front crash prevention system, its standard vehicle-to-pedestrian front crash prevention system, and its standard headlight’s “Acceptable” rating, the Insurance Institute for Highway Safety grants the S90 its highest rating: “Top Safety Pick Plus” for 2022, a rating granted to only 128 vehicles tested by the IIHS. The i4 has not been tested, yet.