Certified Benz & Beemer Compares 2015 Audi A8 VS 2015 Cadillac XTS Near Scottsdale, AZ

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2015 Audi A8

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2015 Cadillac XTS

Safety Comparison

The A8’s pre-crash front seatbelts will tighten automatically in the event the vehicle detects an impending crash, improving protection against injury significantly. The XTS doesn’t offer pre-crash pretensioners.

The A8 has standard Secondary Collision Brake Assist, which automatically apply the brakes in the event of a crash to help prevent secondary collisions and prevent further injuries. The XTS 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 provide maximum traction and stability on all roads, All-Wheel Drive is standard on the A8. But it costs extra on the XTS.

A passive infrared night vision system optional on the A8 helps the driver to more easily detect people, animals or other objects in front of the vehicle at night. Using an infrared camera to detect heat, the system then displays the image on a monitor in the dashboard. The XTS doesn’t offer a night vision system.

The A8 offers an optional Top View Camera System to allow the driver to see objects all around the vehicle on a screen. The XTS 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 A8 and the XTS have standard driver and passenger frontal airbags, front and rear side-impact airbags, driver and front passenger knee airbags, side-impact head airbags, front seatbelt pretensioners, height adjustable front shoulder belts, plastic fuel tanks, four-wheel antilock brakes, traction control, electronic stability systems to prevent skidding, daytime running lights, rear parking sensors, available crash mitigating brakes, lane departure warning systems, blind spot warning systems and rear cross-path warning.

Warranty Comparison

The A8’s corrosion warranty is 6 years longer than the XTS’ (12 vs. 6 years).

Reliability Comparison

To reliably power the ignition and other systems and to recharge the battery, the A8 has a standard 190-amp alternator. The XTS’ 170-amp alternator isn’t as powerful.

The battery on the A8 is in the trunk, which protects it from hot underhood temperatures which can degrade battery life. By keeping the A8’s battery 20 to 30 degrees cooler, its life is increased by years. The XTS’ battery is in the hot engine compartment.

J.D. Power and Associates’ 2014 Initial Quality Study of new car owners surveyed provide the statistics that show that Audi vehicles are better in initial quality than Cadillac vehicles. J.D. Power ranks Audi 11th in initial quality, above the industry average. With 4 more problems per 100 vehicles, Cadillac is ranked 13th.

Engine Comparison

The A8 has more powerful engines than the XTS:



A8 3.0T 3.0 supercharged V6

333 HP

325 lbs.-ft.

A8 4.0T 4.0 turbo V8

435 HP

444 lbs.-ft.

A8 L W12 6.3 DOHC 12 cyl.

500 HP

463 lbs.-ft.


305 HP

264 lbs.-ft.

XTS Vsport 3.6 turbo V6

410 HP

369 lbs.-ft.

The A8’s 3.0 turbo V6 diesel produces 164 lbs.-ft. more torque (428 vs. 264) than the XTS’ standard 3.6 DOHC V6. The A8’s 3.0 turbo V6 diesel produces 59 lbs.-ft. more torque (428 vs. 369) than the XTS Vsport’s standard 3.6 turbo V6.

As tested in Car and Driver the A8 4.0T is faster than the Cadillac XTS V6:



Zero to 60 MPH

3.9 sec

6.9 sec

Zero to 100 MPH

9.8 sec

17.9 sec

5 to 60 MPH Rolling Start

5 sec

7 sec

Quarter Mile

12.4 sec

15.4 sec

Speed in 1/4 Mile

112 MPH

93 MPH

Top Speed

131 MPH

129 MPH

Fuel Economy and Range Comparison

On the EPA test cycle the A8 L TDI gets better fuel mileage than the XTS AWD with its standard engine (24 city/36 hwy vs. 17 city/26 hwy). The A8 L TDI gets better fuel mileage than the XTS AWD with its standard engine (24 city/36 hwy vs. 17 city/26 hwy).

On the EPA test cycle the A8 gets better fuel mileage than the XTS:





18 city/28 hwy

3.6 V6/Auto



19 city/29 hwy

17 city/26 hwy

3.6 V6/Auto


18 city/30 hwy

16 city/24 hwy


An engine control system that can shut down half of the engine’s cylinders helps improve the A8 4.0T/W12’s fuel efficiency. The XTS doesn’t offer a system that can shut down part of the engine.

Regenerative brakes improve the A8’s fuel efficiency by converting inertia back into energy instead of wasting it. The XTS doesn’t offer a regenerative braking system.

In heavy traffic or at stoplights the A8’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 XTS doesn’t offer an automatic engine start/stop system.

The A8 has 4.8 gallons more fuel capacity than the XTS FWD’s standard fuel tank (23.8 vs. 19 gallons), for longer range between fill-ups. The A8 has 3.8 gallons more fuel capacity than the XTS AWD’s standard fuel tank (23.8 vs. 20 gallons).

Brakes and Stopping Comparison

For better stopping power the A8’s brake rotors are larger than those on the XTS:


A8 L W12


Front Rotors

15 inches

15.7 inches

13.6 inches

Rear Rotors

14 inches

14 inches

12.4 inches

The A8 stops much shorter than the XTS:



70 to 0 MPH

169 feet

179 feet

Car and Driver

Tires and Wheels Comparison

For better traction, the A8 has larger standard tires than the XTS (255/45R19 vs. 245/45R19). The A8’s optional tires are larger than the largest tires available on the XTS (265/40R20 vs. 245/45R19).

Suspension and Handling Comparison

The A8 has standard front and rear stabilizer bars, which help keep the A8 flat and controlled during cornering. The XTS’ suspension doesn’t offer a rear stabilizer bar.

The front and rear suspension of the A8 uses air springs for a smoother, controlled ride than the XTS, which uses coil springs in front. Air springs maintain proper ride height and ride more smoothly.

For a smoother ride and more stable handling, the A8’s wheelbase is 6.1 inches longer than on the XTS (117.8 inches vs. 111.7 inches). The A8 L’s wheelbase is 11.2 inches longer than on the XTS (122.9 inches vs. 111.7 inches).

For better handling and stability, the track (width between the wheels) on the A8 is 2.4 inches wider in the front and 1.9 inches wider in the rear than on the XTS.

The A8 handles at .95 G’s, while the XTS AWD pulls only .83 G’s of cornering force in a Motor Trend skidpad test.

The A8 executes Motor Trend’s “Figure Eight” maneuver 1.9 seconds quicker than the XTS AWD (25.7 seconds @ .73 average G’s vs. 27.6 seconds @ .63 average G’s).

Chassis Comparison

The A8 3.0T/4.0T/TDI uses computer-generated active noise cancellation to help remove annoying noise and vibration from the passenger compartment, especially at low frequencies. The XTS doesn’t offer active noise cancellation.

Passenger Space Comparison

The A8 L has 4.5 cubic feet more passenger volume than the XTS (108.7 vs. 104.2).

The A8 has 1.2 inches more front shoulder room, .3 inches more rear headroom and 1.5 inches more rear shoulder room than the XTS.

For enhanced passenger comfort on long trips the A8 L’s available rear seats recline. The XTS’ rear seats don’t recline.

Cargo Capacity Comparison

A low lift-over trunk design makes loading and unloading the A8 L easier. The A8 L’s trunk lift-over height is 27.2 inches, while the XTS’ liftover is 30 inches. The A8’s liftover is only 25.9 inches.

To make loading and unloading groceries and cargo easier when your hands are full, the A8’s trunk can be opened just by kicking your foot under the back bumper, leaving your hands completely free. The A8 also has a standard power trunk, which opens and closes automatically by pressing a button. The XTS doesn’t offer a power or hands-free opening trunk.

Ergonomics Comparison

The A8’s standard easy entry system raises the steering wheel, making it easier for the driver to get in and out. An easy entry system costs extra on the XTS.

If the windows are left down on the A8 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 XTS can only raise the windows from inside the vehicle, with the ignition on.

The A8 has a standard locking fuel door with a remote release located convenient to the driver. A locking fuel door helps prevent vandalism, such as sugar in the tank and fuel theft. The XTS doesn’t offer a locking fuel door.

The A8’s rain-sensitive wipers adjust their speed and turn on and off automatically based on the amount of rainfall on the windshield. This allows the driver to concentrate on driving without constantly adjusting the wipers. The XTS’ standard manually variable intermittent wipers have to be constantly adjusted.

Heated windshield washer nozzles are standard on the A8 to prevent washer fluid and nozzles from freezing and help continue to keep the windshield clear in sub-freezing temperatures. The XTS doesn’t offer heated windshield washer nozzles.

In poor weather, headlights can lose their effectiveness as grime builds up on their lenses. This can reduce visibility without the driver realizing. The A8 has standard headlight washers to keep headlight output high. The XTS doesn’t offer headlight washers.

Optional air conditioned front and rear seats keep the A8’s passengers comfortable and take the sting out of hot leather in Summer. The XTS doesn’t offer air conditioned seats in the rear.

Economic Advantages Comparison

The A8 will cost the buyer less in the long run because of its superior resale value. The Intellichoice estimates that the A8 will retain 38.03% to 43.47% of its original price after five years, while the XTS only retains 34.69% to 36.83%.

Recommendations Comparison

Both the Audi A8 and Cadillac XTS won an award in Kiplinger’s 2015 car issue.

J.D. Power and Associates rated the A8 first among large premium cars in owner reported satisfaction. This includes how well the vehicle performs and satisfies its owner’s expectations. The XTS isn’t in the top three.

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