The X7’s pre-crash front seatbelts will tighten automatically in the event the vehicle detects an impending crash, improving protection against injury significantly. The Ascent doesn’t offer pre-crash pretensioners.
For enhanced safety, the middle seat shoulder belts of the BMW X7 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 Subaru Ascent doesn’t offer height-adjustable middle seat belts.
The BMW X7 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 Ascent doesn’t offer a front passenger side knee airbag.
The X7 has standard Post-Crash Braking, which automatically apply the brakes in the event of a crash to help prevent secondary collisions and prevent further injuries. The Ascent 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 X7 offers an optional Surround View to allow the driver to see objects all around the vehicle on a screen. The Ascent only offers a rear monitor and rear parking sensors that beep or flash a light. That doesn’t help with obstacles to the front or sides.
The X7 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. Only the Ascent Premium/Limited/Touring offers a blind spot warning system.
To help make backing out of a parking space safer, the X7 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. Only the Ascent Premium/Limited/Touring has a rear cross-path warning system.
The X7’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 Ascent doesn’t offer a driver alert monitor.
Both the X7 and the Ascent 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, lane departure warning systems and rearview cameras.
The BMW X7 weighs 794 to 1231 pounds more than the Subaru Ascent. The NHTSA advises that heavier vehicles are much safer in collisions than their significantly lighter counterparts.