Both the G90 and S-Class have child safety locks to prevent children from opening the rear doors. The G90 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 S-Class’ 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.
In the past twenty years hundreds of infants and young children have died after being left in vehicles, usually by accident. When turning the vehicle off, drivers of the G90 are reminded to check the back seat when a sensor determines the back seat is occupied. The S-Class doesn’t offer a back seat reminder.
The G90 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 S-Class doesn’t offer front seat center airbags.
Both the G90 and the S-Class have standard driver and passenger frontal airbags, front and rear 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, rear cross-path warning and driver alert monitors.
For its performance in IIHS driver-side and passenger-side small overlap frontal, moderate overlap frontal, updated side impact, headlight, daytime pedestrian crash prevention, and nighttime pedestrian crash prevention testing, the Insurance Institute for Highway Safety grants the G90 its highest rating: “Top Safety Pick Plus” for 2023, a rating granted to only 67 vehicles tested by the IIHS. The S-Class has not been tested, yet.