The Audi S8 has standard driver and front passenger side knee airbags mounted low on the dashboard. These airbags helps prevent the driver and front passenger from sliding under their seatbelts or the main frontal airbags; this keeps them better positioned during a collision for maximum protection. Knee airbags also help keep the legs from striking the dashboard, preventing knee and leg injuries in the case of a serious frontal collision. The G90 doesn’t offer a front passenger side knee airbag.
The S8 has a standard Secondary Collision Brake Assist, which automatically applies the brakes in the event of a crash to help prevent secondary collisions and prevent further injuries. The G90 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.
Earlier warning of stopped traffic, traffic signals, dangerous road conditions, weather, or accidents, can keep driver's safer and prevent crashes. The S8 has Car-to-X Services, a system that seemlesly communicates important warnings to the driver about impending danger, if they're available. The G90 doesn’t offer a system that can receive automated systems from infrastructure.
A passive infrared night vision system optional on the S8 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 and even aims one of the vehicle’s headlights in the direction of the person or object. The G90 doesn’t offer a night vision system.
Both the S8 and the G90 have standard driver and passenger frontal airbags, front and rear side-impact airbags, driver knee airbags, front seat center airbag, 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, around view monitors, available blind spot warning systems and rear cross-path warning.