For enhanced safety, the front seat shoulder belts of the Audi S8 are height-adjustable to accommodate a wide variety of driver and passenger heights. A better fit can prevent injuries and the increased comfort also encourages passengers to buckle up. The BMW 8 Series Gran Coupe doesn’t offer height-adjustable seat belts.
Both the S8 and 8 Series Gran Coupe have child safety locks to prevent children from opening the rear doors. The S8 has power child safety locks, allowing the driver to activate and deactivate them from the driver's seat and to know when they're engaged. The 8 Series Gran Coupe’s child locks have to be individually engaged at each rear door with a manual switch. The driver can’t know the status of the locks without opening the doors and checking them.
The S8 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 8 Series Gran Coupe doesn’t offer front seat center airbags.
To provide maximum traction and stability on all roads, All-Wheel Drive is standard on the S8. But it costs extra on the 8 Series Gran Coupe.
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 8 Series Gran Coupe doesn’t offer a night vision system.
Both the S8 and the 8 Series Gran Coupe have standard driver and passenger frontal airbags, front side-impact airbags, driver and front passenger knee airbags, side-impact head airbags, front seatbelt pretensioners, four-wheel antilock brakes, traction control, electronic stability systems to prevent skidding, crash mitigating brakes, post-collision automatic braking systems, daytime running lights, lane departure warning systems, rearview cameras, available blind spot warning systems and rear cross-path warning.
The Audi S8 weighs 471 to 1122 pounds more than the BMW 8 Series Gran Coupe. The NHTSA advises that heavier cars are much safer in collisions than their significantly lighter counterparts.