Both the A6 and K900 have child safety locks to prevent children from opening the rear doors. The A6 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 K900’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 A6 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 K900 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 A6 offers all-wheel drive to maximize traction under poor conditions, especially in ice and snow. The K900 doesn’t offer all-wheel drive.
An active infrared night vision system optional on the A6 Prestige helps the driver to more easily detect people, animals or other objects in front of the vehicle at night. Using an infrared camera and near-infrared lights to detect heat, the system then projects the image on the windshield, near the driver’s line of sight. The K900 doesn’t offer a night vision system.
Both the A6 and the K900 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, daytime running lights, rearview cameras, available crash mitigating brakes, lane departure warning systems, blind spot warning systems and around view monitors.
For its top level performance in all IIHS frontal, side, rear impact and roof-crush tests, and with its optional front crash prevention system, the Insurance Institute for Highway Safety grants the A6 the rating of “Top Pick” for 2017, a rating granted to only 120 vehicles tested by the IIHS. The K900 has not been tested, yet.
The A6’s corrosion warranty is 7 years and unlimited miles longer than the K900’s (12/unlimited vs. 5/100,000).
J.D. Power and Associates’ 2016 survey of the owners of three-year-old vehicles provides the long-term dependability statistics that show that Audi vehicles are more reliable than Kia vehicles. J.D. Power ranks Audi 11th in reliability, above the industry average. With 19 more problems per 100 vehicles, Kia is ranked 17th.
From surveys of all its subscribers, Consumer Reports’ April 2017 Auto Issue reports that Audi vehicles are more reliable than Kia vehicles. Consumer Reports ranks Audi fourth in reliability. Kia is ranked fifth.
The A6 3.0T’s standard 3.0 supercharged V6 produces 29 more horsepower (340 vs. 311) and 32 lbs.-ft. more torque (325 vs. 293) than the K900’s standard 3.8 DOHC V6.
On the EPA test cycle the A6 2.0T FWD 7-speed Auto gets better fuel mileage than the K900 V6 (25 city/34 hwy vs. 17 city/25 hwy).
In heavy traffic or at stoplights the A6’s engine automatically turns off when the vehicle is stopped, saving fuel and reducing pollution. The engine is automatically restarted when the driver gets ready to move again. (Start/Stop isn’t accounted in present EPA fuel mileage tests.) The K900 doesn’t offer an automatic engine start/stop system.
The A6 3.0T’s standard front and rear disc brakes are vented to help dissipate heat for shorter stops with less fading. The rear discs on the K900 are solid, not vented.
The A6 stops much shorter than the K900:
60 to 0 MPH
For better traction, the A6’s optional tires are larger than the largest tires available on the K900 (255/40R19 vs. 245/45R19).
The A6’s standard tires provide better handling because they have a lower 45 series profile (height to width ratio) that provides a stiffer sidewall than the K900 V6’s standard 50 series tires. The A6’s optional tires have a lower 35 series profile than the K900 V8 Luxury’s 45 series front and 40 series rear tires.
For better ride, handling and brake cooling the A6 offers optional 20-inch wheels. The K900’s largest wheels are only 19-inches.
The A6 3.0T Premium Plus Quattro handles at .95 G’s, while the K900 V8 Luxury pulls only .80 G’s of cornering force in a Motor Trend skidpad test.
The A6 3.0T Premium Plus Quattro executes Motor Trend’s “Figure Eight” maneuver 3.2 seconds quicker than the K900 V8 Luxury (25.1 seconds @ .74 average G’s vs. 28.3 seconds @ .61 average G’s).
The Audi A6 may be more efficient, handle and accelerate better because it weighs about 450 to 500 pounds less than the Kia K900.
The A6 is 6.4 inches shorter than the K900, making the A6 easier to handle, maneuver and park in tight spaces.
The A6’s standard rear seats fold to accommodate long and bulky cargo. The K900 doesn’t offer folding rear seats, only a ski pass-through.
Unlike the driver-only memory system in the K900, the A6 Prestige offers an optional passenger memory, so that when drivers switch, the memory setting adjusts the driver’s seat, steering wheel position (with optional power wheel adjuster), outside mirror angle and climate settings and the front passenger seat also adjusts to the new passenger’s preset preferences.
If the windows are left down on the A6 the driver can raise them all using the key in the outside lock cylinder; on a hot day the driver can lower the windows. The driver of the K900 can only operate the windows from inside the vehicle, with the ignition on.
Heated windshield washer nozzles are standard on the A6 to prevent washer fluid and nozzles from freezing and help continue to keep the windshield clear in sub-freezing temperatures. The K900 doesn’t offer heated windshield washer nozzles.
While driving with high beams on, sensitive light sensors available for the A6 detect other vehicles which could be blinded and automatically switch to low beams. The K900 doesn’t offer automatic dimming high beams.
Consumer Reports® recommends the Audi A6, based on reliability, safety and performance.
The A6 was chosen as one of Car and Driver’s “Top Ten” for 5 of the last 18 years. The K900 has never been a Car and Driver “Top Ten” pick.
The Audi A6/S6 outsold the Kia K900 by almost 30 to one during the 2017 model year.