The 4 Series Gran Coupe’s pre-crash front seatbelts will tighten automatically in the event the vehicle detects an impending crash, improving protection against injury significantly. The CT4 doesn’t offer pre-crash pretensioners.
The 4 Series Gran 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 CT4 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 4 Series Gran Coupe’s standard lane departure warning system alerts a temporarily inattentive driver when the vehicle begins to leave its lane. A lane departure warning system costs extra on the CT4 and is only available on CT4 Premium Luxury/Sport.
The 4 Series Gran Coupe has a standard blind spot warning system which 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 CT4’s blind spot costs extra.
To help make backing out of a parking space safer, the 4 Series Gran Coupe has a standard cross-path warning system, which uses sensors in the rear bumper to alert the driver to vehicles approaching from the side, helping the driver avoid collisions. Only the CT4 Premium Luxury/Sport offers a cross-path warning system and it costs extra.
The 4 Series Gran 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 CT4 doesn’t offer a driver alert monitor.
Both the 4 Series Gran Coupe and the CT4 have standard driver and passenger frontal airbags, front side-impact airbags, driver and front passenger knee airbags, side-impact head airbags, front seatbelt pretensioners, plastic fuel tanks, four-wheel antilock brakes, traction control, electronic stability systems to prevent skidding, crash mitigating brakes, daytime running lights, rearview cameras and available all wheel drive.