The S-Class’ pre-crash front seatbelts will tighten automatically in the event the vehicle detects an impending crash, improving protection against injury significantly. The Quattroporte doesn’t offer pre-crash pretensioners.
The Mercedes S-Class has a standard driver’s side knee airbag mounted low on the dashboard. The knee airbag helps prevent the driver from sliding under the seatbelts or the main frontal airbag; this keeps the driver better positioned during a collision for maximum protection. A knee airbag also helps keep the legs from striking the dashboard, preventing knee and leg injuries in the case of a serious frontal collision. The Quattroporte doesn’t offer knee airbags.
The rear seatbelts optional on the 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 Quattroporte doesn’t offer inflatable seatbelts.
The S-Class has standard Post-Collision Brake, which automatically apply the brakes in the event of a crash to help prevent secondary collisions and prevent further injuries. The Quattroporte 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 S-Class has standard Maneuvering Brake Function that use rear sensors to monitor for objects to the rear and automatically apply the brakes to prevent a collision. The Quattroporte doesn’t offer backup collision prevention brakes.
To provide maximum traction and stability on all roads, All-Wheel Drive is standard on the S-Class. But it costs extra on the Quattroporte.
Earlier warning of stopped traffic, traffic signals, dangerous road conditions, weather, or accidents, can keep driver's safer and prevent crashes. The S-Class has Car-to-X Communication, a system that seemlesly communicates important warnings to the driver about impending danger, if they're available. The Quattroporte doesn’t offer a system that can receive automated systems from infrastructure or other vehicles.
Both the S-Class and Quattroporte have rear cross-traffic warning, but the S-Class has Active Brake Assist (automatically applies the brakes) to better prevent a collision when backing near traffic. The Quattroporte’s Rear Cross Path doesn’t automatically brake.
The 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 Quattroporte doesn’t offer a driver alert monitor.
Both the S-Class and the Quattroporte have standard driver and passenger frontal airbags, front side-impact airbags, side-impact head airbags, front and rear seatbelt pretensioners, height adjustable front shoulder belts, 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, around view monitors and rear cross-path warning.