For enhanced safety, the front and rear seat shoulder belts of the Audi S5 have pretensioners to tighten the seatbelts and eliminate dangerous slack in the event of a collision and force limiters to limit the pressure the belts will exert on the passengers. The BMW M2 doesn’t offer pretensioners for the rear seat belts.
The S5’s pre-crash front seatbelts will tighten automatically in the event the vehicle detects an impending crash, improving protection against injury significantly. The M2 doesn’t offer pre-crash pretensioners.
The S5’s standard pretensioning seatbelts also sense rear collisions and remove slack from the seatbelts to help protect the occupants from whiplash and other injuries. The M2 doesn’t offer a whiplash protection system.
The S5 has a standard Secondary Collision Brake Assist, which automatically applies the brakes in the event of a crash to help prevent secondary collisions and prevent further injuries. The M2 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 S5 has all-wheel drive to maximize traction under poor conditions, especially in ice and snow. The M2 doesn’t offer all-wheel drive.
The S5 Premium Plus/Prestige has a standard Top View Cameras to allow the driver to see objects all around the vehicle on a screen. The M2 only offers a rear monitor and front and rear parking sensors that beep or flash a light. That doesn’t help with obstacles to the sides.
The S5’s optional blind spot warning system uses sensors to alert the driver to objects in the vehicle’s blind spots where the side view mirrors don’t reveal them. The M2 doesn’t offer a system to reveal objects in the driver’s blind spots.
To help make backing out of a parking space safer, the S5’s optional 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 M2 doesn’t offer a cross-path warning system.
Both the S5 and the M2 have standard driver and passenger frontal airbags, front side-impact airbags, driver and front passenger knee airbags, side-impact head airbags, 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 and rearview cameras.
For its top level performance in all IIHS frontal, side, rear impact and roof-crush tests, and its standard front crash prevention system, the Insurance Institute for Highway Safety grants the S5 the rating of “Top Pick” for 2017, a rating granted to only 205 vehicles tested by the IIHS. The M2 has not been tested, yet.