The Cullinan’s pre-crash front seatbelts will tighten automatically in the event the vehicle detects an impending crash, improving protection against injury significantly. The MDX doesn’t offer pre-crash pretensioners.
Both the Cullinan and MDX have child safety locks to prevent children from opening the rear doors. The Cullinan 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 MDX’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 Cullinan’s standard pretensioning seatbelts also sense rear collisions and remove slack from the seatbelts to help protect the occupants from whiplash and other injuries. The MDX doesn’t offer a whiplash protection system.
The Cullinan has standard PostCrash, which automatically apply the brakes in the event of a crash to help prevent secondary collisions and prevent further injuries. The MDX 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 Cullinan. But it costs extra on the MDX.
When descending a steep, off-road slope, the Cullinan’s standard Hill Descent Control allows you to creep down safely. The MDX doesn’t offer Hill Descent Control.
A passive infrared night vision system optional on the Cullinan 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 MDX doesn’t offer a night vision system.
Both the Cullinan and the MDX have standard driver and passenger frontal airbags, front side-impact airbags, driver and front passenger 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 driver alert monitors.
The Rolls-Royce Cullinan weighs 1513 to 2043 pounds more than the Acura MDX. The NHTSA advises that heavier vehicles are much safer in collisions than their significantly lighter counterparts.