The X5’s pre-crash front seatbelts will tighten automatically in the event the vehicle detects an impending crash, improving protection against injury significantly. The Envision doesn’t offer pre-crash pretensioners.
The BMW X5 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 Envision doesn’t offer a front passenger side knee airbag.
The X5 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 Envision doesn’t offer a whiplash protection system.
The X5 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 Envision 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.
Both the X5 and Envision have rear cross-traffic warning, but the X5 has Cross Traffic Warning with Braking (automatically applies the brakes) to better prevent a collision when backing near traffic. The Envision’s Rear Cross Traffic Alert doesn’t automatically brake.
The X5’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 Envision doesn’t offer a driver alert monitor.
Both the X5 and the Envision 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, daytime running lights, lane departure warning systems, blind spot warning systems, rearview cameras, rear cross-path warning and available all wheel drive.
The BMW X5 weighs 987 to 1881 pounds more than the Buick Envision. The NHTSA advises that heavier vehicles are much safer in collisions than their significantly lighter counterparts.