The X3’s pre-crash front seatbelts will tighten automatically in the event the vehicle detects an impending crash, improving protection against injury significantly. The 4Runner doesn’t offer pre-crash pretensioners.
The X3 has a standard front seat center airbag, which deploys between the driver and front passenger, protecting them from injuries caused by striking each other in serious side impacts. The 4Runner doesn’t offer front seat center airbags.
The X3 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 4Runner doesn’t offer a whiplash protection system.
To provide maximum traction and stability on all roads, All-Wheel Drive is standard on the X3. But it costs extra on the 4Runner.
To help make backing out of a parking space safer, the X3 has standard Cross Traffic Warning with braking function with automatic braking, systems which detect vehicles approaching from the sides and can automatically apply the brakes to prevent a collision. Only the 4Runner Limited/Platinum/Trailhunter/TRD Pro offers Parking Support Brake.
For better protection of the passenger compartment, the X3 uses safety cell construction with a three-dimensional high-strength frame that surrounds the passenger compartment. It provides extra impact protection and a sturdy mounting location for door hardware and side impact beams. The 4Runner uses a body-on-frame design, which has no frame members above the floor of the vehicle.
Both the X3 and the 4Runner have standard driver and passenger frontal airbags, front side-impact airbags, driver and front passenger knee airbags, side-impact head airbags, front and rear 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, driver alert monitors and available around view monitors.

