The GLS offers an optional Post Collision Brake, which automatically applies the brakes in the event of a crash to help prevent secondary collisions and prevent further injuries. The QX60 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.
To provide maximum traction and stability on all roads, All-Wheel Drive is standard on the GLS. But it costs extra on the QX60.
Both the GLS and the QX60 have standard driver and passenger frontal airbags, front side-impact airbags, driver knee 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, blind spot warning systems, rearview cameras, rear cross-path warning and available lane departure warning systems.
The Mercedes GLS weighs 812 to 1692 pounds more than the Infiniti QX60. The NHTSA advises that heavier vehicles are much safer in collisions than their significantly lighter counterparts.

