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 RDX doesn’t offer pre-crash pretensioners.
Both the Cayenne Coupe and RDX 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 RDX’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 RDX 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.
Over 200 people are killed each year when backed over by motor vehicles. The Cayenne Coupe has standard Maneuver Assist that uses rear sensors to monitor for objects to the rear and automatically applies the brakes to prevent a collision. The RDX doesn’t offer backup collision prevention brakes.
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 RDX doesn’t offer a night vision system.
Both the Cayenne Coupe and RDX have rear cross-traffic warning, but the Cayenne Coupe has Rear Cross Traffic Alert (automatically applies the brakes) to better prevent a collision when backing near traffic. The RDX’s Rear Cross Traffic Monitor 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 RDX doesn’t offer a driver alert monitor.
Both the Cayenne Coupe and the RDX have standard driver and passenger frontal airbags, front 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 682 to 1705 pounds more than the Acura RDX. The NHTSA advises that heavier vehicles are much safer in collisions than their significantly lighter counterparts.