The XC40’s pre-crash front seatbelts will tighten automatically in the event the vehicle detects an impending crash, improving protection against injury significantly. The NX doesn’t offer pre-crash pretensioners.
Both the XC40 and NX have child safety locks to prevent children from opening the rear doors. The XC40 Ultra 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 NX’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 XC40 has a standard Whiplash Protection System (WHIPS), which use a specially designed seat to protect the driver and front passenger from whiplash. During a rear-end collision, the WHIPS allows the backrest to travel backwards to cushion the occupants and the headrests move forward to prevent neck and spine injuries. At the same time the pretensioning seatbelts fire, removing slack from the belts. The NX doesn’t offer a whiplash protection system.
The XC40 has standard Post-impact braking, which automatically apply the brakes in the event of a crash to help prevent secondary collisions and prevent further injuries. The NX 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 XC40. But it costs extra on the NX.
Both the XC40 and the NX 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, plastic fuel tanks, 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, driver alert monitors and available around view monitors.