The A4’s pre-crash front seatbelts will tighten automatically in the event the vehicle detects an impending crash, improving protection against injury significantly. The Civic Si doesn’t offer pre-crash pretensioners.
Both the A4 and Civic Si have child safety locks to prevent children from opening the rear doors. The A4 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 Civic Si’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.
The A4 has a standard Audi Backguard System, which use a specially designed headrest to protect the driver and front passenger from whiplash. During a rear-end collision, the Audi Backguard System moves the headrests forward to prevent neck and spine injuries. At the same time the pretensioning seatbelts fire, removing slack from the belts. The Civic Si doesn’t offer a whiplash protection system.
The A4 has a standard Secondary Collision Brake Assist, which automatically applies the brakes in the event of a crash to help prevent secondary collisions and prevent further injuries. The Civic Si 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 A4 has all-wheel drive to maximize traction under poor conditions, especially in ice and snow. The Civic Si doesn’t offer all-wheel drive.
When descending a steep, off-road slope, the A4’s standard Hill Descent Control allows you to creep down safely. The Civic Si doesn’t offer Hill Descent Control.
The A4 Premium Plus/Prestige has a standard Top and Corner View Cameras to allow the driver to see objects all around the vehicle on a screen. The Civic Si only offers a rear monitor.
The A4 has a standard Audi Connect CARE, which uses a global positioning satellite (GPS) receiver and a cellular system to help track down your vehicle if it’s stolen or send emergency personnel to the scene if any airbags deploy. The Civic Si doesn’t offer a GPS response system, so if you’re involved in an accident and you’re incapacitated help may not come as quickly.
Both the A4 and the Civic Si have standard driver and passenger frontal airbags, front side-impact airbags, driver and front passenger knee airbags, side-impact head airbags, front and rear seatbelt pretensioners, height adjustable front shoulder belts, plastic fuel tanks, four-wheel antilock brakes, traction control, electronic stability systems to prevent skidding, crash mitigating brakes, daytime running lights, rearview cameras, available blind spot warning systems and rear cross-path warning.
The Audi A4 weighs 511 to 721 pounds more than the Honda Civic Si. The NHTSA advises that heavier cars are much safer in collisions than their significantly lighter counterparts. Crosswinds also affect lighter cars more.
For its top level performance in IIHS driver and passenger-side small overlap frontal, moderate overlap frontal, side impact, roof strength and head restraint tests, its standard vehicle-to-vehicle front crash prevention system, its standard vehicle-to-pedestrian front crash prevention system, and its available headlight’s “Good” rating, the Insurance Institute for Highway Safety grants the A4 the rating of “Top Safety Pick” for 2022, a rating granted to only 155 vehicles tested by the IIHS. The Civic Si has not been tested, yet.


