The i4’s pre-crash front seatbelts will tighten automatically in the event the vehicle detects an impending crash, improving protection against injury significantly. The MX-30 doesn’t offer pre-crash pretensioners.
The i4 has a standard PostCrash iBrake, which automatically applies the brakes in the event of a crash to help prevent secondary collisions and prevent further injuries. The MX-30 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.
The i4 M50 has all-wheel drive to maximize traction under poor conditions, especially in ice and snow. The MX-30 doesn’t offer all-wheel drive.
To help make backing out of a parking space safer, the i4’s standard rear cross-path warning system uses sensors in the rear bumper to alert the driver to vehicles approaching from the side, helping the driver avoid collisions. The MX-30 doesn’t offer a cross-path warning system.
Both the i4 and the MX-30 have standard driver and passenger frontal airbags, front side-impact airbags, driver and front passenger knee airbags, side-impact head airbags, front seatbelt pretensioners, 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, driver alert monitors and available around view monitors.
The BMW i4 weighs 1010 to 1363 pounds more than the Mazda MX-30. The NHTSA advises that heavier cars are much safer in collisions than their significantly lighter counterparts.