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 GTI doesn’t offer pre-crash pretensioners.
Both the S5 and GTI have child safety locks to prevent children from opening the rear doors. The S5 has power child safety locks, allowing the driver to activate and deactivate them from the driver's seat and to know when they're engaged. The GTI’s child locks have to be individually engaged at each rear door with a manual switch. The driver can’t know the status of the locks without opening the doors and checking them.
In the past twenty years hundreds of infants and young children have died after being left in vehicles, usually by accident. When turning the vehicle off, drivers of the S5 are reminded to check the back seat if they opened the rear door before starting out. The GTI doesn’t offer a back seat reminder.
The Audi S5 has standard driver and front passenger side knee airbags mounted low on the dashboard. These airbags help prevent the driver and front passenger from sliding under their seatbelts or the main frontal airbags; this keeps them better positioned during a collision for maximum protection. Knee airbags also help keep the legs from striking the dashboard, preventing knee and leg injuries in the case of a serious frontal collision. The GTI doesn’t offer knee airbags.
The S5 has all-wheel drive to maximize traction under poor conditions, especially in ice and snow. The GTI doesn’t offer all-wheel drive.
Earlier warning of stopped traffic, traffic signals, dangerous road conditions, weather, or accidents, can keep driver's safer and prevent crashes. The S5 has Car-to-X Services, a system that seamlessly communicates important warnings to the driver about impending danger, if they're available. The GTI doesn’t offer a system that can receive automated systems from infrastructure.
The S5 offers an optional Top View Camera System to allow the driver to see objects all around the vehicle on a screen. The GTI 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.
Both the S5 and the GTI have standard driver and passenger frontal airbags, front side-impact airbags, side-impact head airbags, front seatbelt pretensioners, height adjustable front shoulder belts, four-wheel antilock brakes, traction control, electronic stability systems to prevent skidding, crash mitigating brakes, post-collision automatic braking systems, daytime running lights, lane departure warning systems, blind spot warning systems, rearview cameras, rear cross-path warning and driver alert monitors.
The Audi S5 weighs 1105 pounds more than the Volkswagen GTI. The NHTSA advises that heavier cars are much safer in collisions than their significantly lighter counterparts. Crosswinds also affect lighter cars more.