The rear seatbelts optional on the AMG S-Class inflate when a collision is detected, helping to spread crash forces over a much larger area of the body and limiting head and neck movement. This can help prevent spinal and internal injuries. The S8 doesn’t offer inflatable seatbelts.
The AMG S-Class’ standard pretensioning seatbelts also sense rear collisions and remove slack from the seatbelts to help protect the occupants from whiplash and other injuries. The S8 doesn’t offer a whiplash protection system.
Over 200 people are killed each year when backed over by motor vehicles. The AMG S-Class has a standard Maneuvering Brake that uses rear sensors to monitor for objects to the rear and automatically applies the brakes to prevent a collision. The S8 doesn’t offer automatic braking for stationary objects directly to the rear.
The AMG S-Class has a standard blind spot warning system that uses sensors to alert the driver to objects in the vehicle’s blind spots where the side view mirrors don’t reveal them and moves the vehicle back into its lane. A system to reveal vehicles in the S8’s blind spot costs extra.
To help make backing out of a parking space safer, the AMG S-Class has standard Rear Cross-Traffic Alert and Rear Cross Traffic Brake automatically engages the brakes to help avoid a collision. Audi charges extra for Rear Cross-Traffic Assist on the S8.
The AMG S-Class’ 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 S8 doesn’t offer a driver alert monitor.
Both the AMG S-Class and the S8 have standard driver and passenger frontal airbags, front side-impact airbags, driver knee airbags, side-impact head airbags, front and rear 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, post-collision automatic braking systems, daytime running lights, lane departure warning systems and around view monitors.
The Mercedes AMG S-Class weighs 594 pounds more than the Audi S8. The NHTSA advises that heavier cars are much safer in collisions than their significantly lighter counterparts.