Both the Q8 and GLC Coupe have child safety locks to prevent children from opening the rear doors. The Q8 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 GLC 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 Q8 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 GLC Coupe 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.
When descending a steep, off-road slope, the Q8’s standard Hill Descent Assist allows you to creep down safely. The GLC Coupe doesn’t offer Hill Descent Assist.
A passive infrared night vision system optional on the Q8 Prestige 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. The GLC Coupe doesn’t offer a night vision system.
The Q8’s standard lane departure warning system alerts a temporarily inattentive driver when the vehicle begins to leave its lane. A lane departure warning system costs extra on the GLC Coupe.
Both the Q8 and the GLC Coupe 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, all wheel drive, traction control, electronic stability systems to prevent skidding, crash mitigating brakes, daytime running lights, blind spot warning systems, rearview cameras, rear cross-path warning and available around view monitors.
The Audi Q8 weighs 1036 pounds more than the Mercedes GLC Coupe. The NHTSA advises that heavier vehicles are much safer in collisions than their significantly lighter counterparts.
For its top level performance in IIHS driver and passenger-side small overlap frontal, moderate overlap frontal, side impact, roof strength and head restraint tests, its standard vehicle-to-vehicle front crash prevention system, its standard vehicle-to-pedestrian front crash prevention system, and its standard headlight’s “Acceptable” rating, the Insurance Institute for Highway Safety grants the Q8 its highest rating: “Top Safety Pick Plus” for 2022, a rating granted to only 127 vehicles tested by the IIHS. The GLC Coupe has not been tested, yet.