The 4 Series Coupe’s pre-crash front seatbelts will tighten automatically in the event the vehicle detects an impending crash, improving protection against injury significantly. The 718 Cayman doesn’t offer pre-crash pretensioners.
The 4 Series Coupe’s standard pretensioning seatbelts also sense rear collisions and remove slack from the front seatbelts to help protect the occupants from whiplash and other injuries. The 718 Cayman doesn’t offer a whiplash protection system.
The 4 Series Coupe 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 718 Cayman 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.
Over 200 people are killed each year when backed over by motor vehicles. The 4 Series Coupe offers an optional Active Park Distance Control that uses rear sensors to monitor for objects to the rear and automatically applies the brakes to prevent a collision. The 718 Cayman doesn’t offer backup collision prevention brakes.
The 4 Series Coupe offers all-wheel drive to maximize traction under poor conditions, especially in ice and snow. The 718 Cayman doesn’t offer all-wheel drive.
The 4 Series Coupe’s lane departure warning system alerts a temporarily inattentive driver when the vehicle begins to leave its lane and gently nudges the vehicle back towards its lane. The 718 Cayman doesn’t offer a lane departure warning system.
The 4 Series Coupe offers an optional Surround View to allow the driver to see objects all around the vehicle on a screen. The 718 Cayman 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 4 Series Coupe has a standard blind spot warning system that uses sensors to alert the driver to objects in the vehicle’s blind spots where the side view mirrors don’t reveal them and moves the vehicle back into its lane. A system to reveal vehicles in the 718 Cayman’s blind spot costs extra.
To help make backing out of a parking space safer, the 4 Series Coupe’s standard Cross Traffic Warning uses sensors in the rear to alert the driver to vehicles approaching from the side, helping the driver avoid collisions. The 718 Cayman doesn’t offer a rear cross-path warning system.
The 4 Series Coupe’s driver alert monitor detects an inattentive driver then sounds a warning and suggests a break. According to the NHTSA, drivers who fall asleep cause about 100,000 crashes and 1500 deaths a year. The 718 Cayman doesn’t offer a driver alert monitor.
Both the 4 Series Coupe and the 718 Cayman 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, daytime running lights and rearview cameras.