The 4 Series Gran Coupe has standard City Collision Mitigation, which use forward mounted sensors to warn the driver of a possible collision ahead. If the driver doesn’t react and the system determines a collision is imminent, it automatically applies the brakes at full-force in order to reduce the force of the crash or avoid it altogether. The A3 has a collision warning system without the crash-mitigating brake feature that could reduce stopping distances.
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 A3 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 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. Cross-path warning costs extra on the A3.
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 A3 doesn’t offer a driver alert monitor.
Both the 4 Series Gran Coupe and the A3 have standard driver and passenger frontal airbags, front side-impact airbags, side-impact head airbags, four-wheel antilock brakes, traction control, electronic stability systems to prevent skidding, collision warning systems, daytime running lights, lane departure warning systems, rearview cameras and available all wheel drive.