The Cayenne Coupe’s pre-crash front seatbelts will tighten automatically in the event the vehicle detects an impending crash, improving protection against injury significantly. The QX55 doesn’t offer pre-crash pretensioners.
Both the Cayenne Coupe and QX55 have child safety locks to prevent children from opening the rear doors. The Cayenne Coupe 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 QX55’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 Cayenne Coupe 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 QX55 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.
When descending a steep, off-road slope, the Cayenne Coupe’s standard Porsche Hill Control allows you to creep down safely. The QX55 doesn’t offer Porsche Hill Control.
A passive infrared night vision system optional on the Cayenne Coupe 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 QX55 doesn’t offer a night vision system.
Both the Cayenne Coupe and QX55 have Rear Cross Traffic Alert, but the Cayenne Coupe has automatic rear cross-traffic braking (automatically applies the brakes) to better prevent a collision when backing near traffic. The QX55’s Rear Cross Traffic Alert doesn’t automatically brake.
The Cayenne Coupe’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 QX55 doesn’t offer a driver alert monitor.
Both the Cayenne Coupe and the QX55 have standard driver and passenger frontal airbags, front and rear side-impact airbags, driver and front passenger knee airbags, side-impact head airbags, front seatbelt pretensioners, height adjustable front shoulder belts, 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, blind spot warning systems, rearview cameras and rear cross-path warning.
The Porsche Cayenne Coupe weighs 617 to 1649 pounds more than the Infiniti QX55. The NHTSA advises that heavier vehicles are much safer in collisions than their significantly lighter counterparts.