The EQS’ pre-crash front seatbelts will tighten automatically in the event the vehicle detects an impending crash, improving protection against injury significantly. The Ioniq 5 doesn’t offer pre-crash pretensioners.
The Mercedes EQS 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 Ioniq 5 doesn’t offer knee airbags.
The rear seatbelts optional on the EQS 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 Ioniq 5 doesn’t offer inflatable seatbelts.
The EQS’ standard pretensioning seatbelts also sense rear collisions and remove slack from the seatbelts to help protect the occupants from whiplash and other injuries. The Ioniq 5 doesn’t offer a whiplash protection system.
The EQS has a standard Post Collision Brake, which automatically applies the brakes in the event of a crash to help prevent secondary collisions and prevent further injuries. The Ioniq 5 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 EQS has Car-to-X Communication, a system that seamlessly communicates important warnings to the driver about impending danger, if they're available. The Ioniq 5 doesn’t offer a system that can receive automated systems from infrastructure or other vehicles.
Both the EQS and the Ioniq 5 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, traction control, electronic stability systems to prevent skidding, crash mitigating brakes, daytime running lights, lane departure warning systems, blind spot warning systems, rearview cameras, rear cross-path warning and driver alert monitors.
The Mercedes EQS weighs 782 to 1841 pounds more than the Hyundai Ioniq 5. The NHTSA advises that heavier cars are much safer in collisions than their significantly lighter counterparts.