The Cayenne has a standard Multi-collision Brake System, which automatically applies the brakes in the event of a crash to help prevent secondary collisions and prevent further injuries. The QX50 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.
To provide maximum traction and stability on all roads, All-Wheel Drive is standard on the Cayenne. But it costs extra on the QX50.
When descending a steep, off-road slope, the Cayenne’s standard Porsche Hill Control allows you to creep down safely. The QX50 doesn’t offer Porsche Hill Control.
A passive infrared night vision system optional on the Cayenne helps the driver to more easily detect people, animals or other objects in front of the vehicle at night. Using an infrared camera to detect heat, the system then displays the image on a monitor in the dashboard. The QX50 doesn’t offer a night vision system.
Both the Cayenne and QX50 have Rear Cross Traffic Alert, but the Cayenne has automatic rear cross-traffic braking (automatically applies the brakes) to better prevent a collision when backing near traffic. The QX50’s Rear Cross Traffic Alert doesn’t automatically brake.
Both the Cayenne and the QX50 have standard driver and passenger frontal airbags, front and rear side-impact airbags, driver and front passenger knee airbags, side-impact head airbags, height adjustable front shoulder belts, 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 around view monitors.
The Porsche Cayenne weighs 498 to 1815 pounds more than the Infiniti QX50. The NHTSA advises that heavier vehicles are much safer in collisions than their significantly lighter counterparts.

