The Vantage’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 Vantage has a standard 3D Surround View System 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 Vantage 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. 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 Vantage’s standard Rear Cross Traffic Assist uses sensors in the rear to alert the driver to vehicles approaching from the side and automatically engage the brakes. The 718 Cayman doesn’t offer a rear cross-path warning system.
The Vantage’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 Vantage and the 718 Cayman have standard driver and passenger frontal 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.
The Aston Martin Vantage weighs 516 to 710 pounds more than the Porsche 718 Cayman. The NHTSA advises that heavier cars are much safer in collisions than their significantly lighter counterparts.