The Phantom has standard whiplash protection, which use a specially designed headrest to protect the driver and front passenger from whiplash. During a rear-end collision, the whiplash protection system moves the headrests forward to prevent neck and spine injuries. At the same time the pretensioning seatbelts fire, removing slack from the belts. The CLS doesn’t offer a whiplash protection system.
The Phantom has standard PostCrash, which automatically apply the brakes in the event of a crash to help prevent secondary collisions and prevent further injuries. The CLS 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.
An active infrared night vision system standard on the Phantom helps the driver to more easily detect people, animals or other objects in front of the vehicle at night. Using an infrared camera and near-infrared lights to detect heat, the system then displays the image on a monitor in the dashboard and even aims one of the vehicle’s headlights in the direction of the person or object. The CLS doesn’t offer a night vision system.
The Phantom’s standard lane departure warning system alerts a temporarily inattentive driver when the vehicle begins to leave its lane. A lane departure warning system costs extra on the CLS.
To help make backing out of a parking space safer, the Phantom has standard Cross Traffic Warning, helping the driver avoid collisions. Mercedes charges extra for Rear Cross-Traffic Alert on the CLS.
Both the Phantom and the CLS have standard driver and passenger frontal airbags, front side-impact airbags, driver 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, daytime running lights, blind spot warning systems, rearview cameras and driver alert monitors.
The Rolls-Royce Phantom weighs 1499 to 1609 pounds more than the Mercedes CLS. The NHTSA advises that heavier cars are much safer in collisions than their significantly lighter counterparts.