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 S-Class has a standard front seat center airbag, which deploys between the driver and front passenger, protecting them from injuries caused by striking each other in serious side impacts. The Quattroporte doesn’t offer front seat center 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 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 Quattroporte doesn’t offer backup collision prevention brakes.
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 seamlessly 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 Rear Cross Traffic Brake (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, 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, daytime running lights, lane departure warning systems, blind spot warning systems, around view monitors and rear cross-path warning.
The Mercedes S-Class weighs 507 to 1268 pounds more than the Maserati Quattroporte. The NHTSA advises that heavier cars are much safer in collisions than their significantly lighter counterparts.