SONS Automotive Group Compares 2018 Cadillac CT6 VS 2018 Audi S8 Near Tucker, GA

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2018 Cadillac CT6

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2018 Cadillac CT6

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2018 Audi S8

Safety Comparison

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 CT6 are reminded to check the back seat if they opened the rear door before starting out. The S8 doesn’t offer a back seat reminder.

Over 200 people are killed each year when backed over by motor vehicles. The CT6 (except Base/Luxury) offers optional Reverse Automatic Braking which use rear sensors to monitor and automatically apply the brakes to prevent a rear collision. The S8 doesn’t offer backup collision prevention brakes.

To help make backing safer, the CT6’s optional cross-path warning system uses wide-angle radar in the rear bumper to alert the driver to vehicles approaching from the side, helping the driver avoid collisions. The S8 doesn’t offer a cross-path warning system.

The CT6 has standard OnStar®, which uses a global positioning satellite (GPS) receiver and a cellular system to get turn-by-turn driving directions, remotely unlock your doors if you lock your keys in, help track down your vehicle if it’s stolen or send emergency personnel to the scene if any airbags deploy. The S8 doesn’t offer a GPS response system, only a navigation computer with no live response for emergencies, so if you’re involved in an accident and you’re incapacitated help may not come as quickly.

Both the CT6 and the S8 have standard driver and passenger frontal airbags, front 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, rearview cameras, available crash mitigating brakes, night vision systems, lane departure warning systems, blind spot warning systems and around view monitors.

Warranty Comparison

Cadillac’s powertrain warranty covers the CT6 2 years and 20,000 miles longer than Audi covers the S8. Any repair needed on the engine, transmission, axles, joints or driveshafts is fully covered for 6 years or 70,000 miles. Coverage on the S8 ends after only 4 years or 50,000 miles.

Cadillac pays for scheduled maintenance on the CT6 for 3 years and 36,000 miles. Cadillac will pay for oil changes, lubrication and any other required maintenance. Audi only pays for the first scheduled maintenance visit on the S8.

There are over 3 times as many Cadillac dealers as there are Audi dealers, which makes it much easier should you ever need service under the CT6’s warranty.

Reliability Comparison

J.D. Power and Associates’ 2017 Initial Quality Study of new car owners surveyed provide the statistics that show that Cadillac vehicles are better in initial quality than Audi vehicles. J.D. Power ranks Cadillac 20th in initial quality. With 10 more problems per 100 vehicles, Audi is ranked 26th.

Fuel Economy and Range Comparison

On the EPA test cycle the CT6 AWD turbo V6 gets better fuel mileage than the S8 Plus (18 city/26 hwy vs. 14 city/24 hwy).

In heavy traffic or at stoplights the CT6’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 S8 doesn’t offer an automatic engine start/stop system.

The CT6 has a standard cap-less fueling system. The fuel filler is automatically opened when the fuel nozzle is inserted and automatically closed when it’s removed. This eliminates the need to unscrew and replace the cap and it reduces fuel evaporation, which causes pollution. The S8 doesn’t offer a cap-less fueling system.

Brakes and Stopping Comparison

The CT6 stops shorter than the S8:





70 to 0 MPH

152 feet

156 feet

Car and Driver

60 to 0 MPH

106 feet

107 feet

Motor Trend

Suspension and Handling Comparison

For a smoother ride and more stable handling, the CT6’s wheelbase is 4.5 inches longer than on the S8 (122.4 inches vs. 117.9 inches).

The CT6’s front to rear weight distribution is more even (51.2% to 48.8%) than the S8’s (56.4% to 43.6%). This gives the CT6 more stable handling and braking.

Chassis Comparison

The Cadillac CT6 may be more efficient, handle and accelerate better because it weighs about 300 to 1050 pounds less than the Audi S8.

The front grille of the CT6 uses electronically controlled shutters to close off airflow and reduce drag when less engine cooling is needed. This helps improve highway fuel economy. The S8 doesn’t offer active grille shutters.

As tested by Car and Driver while at idle, the interior of the CT6 is quieter than the S8 Plus (42 vs. 43 dB).

Passenger Space Comparison

Because it has more passenger and cargo room, the CT6 is rated a Large car by the EPA, while the S8 is rated a Mid-size.

The CT6 has 19.3 cubic feet more passenger volume than the S8 (121.2 vs. 101.9).

The CT6 has 2.9 inches more front headroom, 1 inch more front legroom and 1.7 inches more rear legroom than the S8.

For enhanced passenger comfort on long trips the CT6’s available rear seats recline. The S8’s rear seats don’t recline.

Cargo Capacity Comparison

The CT6 has a much larger trunk than the S8 (15.3 vs. 14.2 cubic feet).

Ergonomics Comparison

The CT6 has a standard remote vehicle starting system, so the vehicle can be started from inside the driver's house. This allows the driver to comfortably warm up the engine before going out to the vehicle. The climate system will also automatically heat or cool the interior. The S8 doesn’t offer a remote starting system.

The CT6’s instruments include an oil pressure gauge and a temperature gauge – which could save your engine! Often ‘idiot lights’ don’t warn you until damage has been done. The S8 does not have an oil pressure gauge.

On a hot day the CT6’s driver can lower all the windows from a distance using the keyless remote. The driver of the S8 can’t use the remote to operate the windows.

Optional air conditioned front and rear seats keep the CT6’s passengers comfortable and take the sting out of hot leather in Summer. The S8 doesn’t offer air-conditioned seats in the rear.

Standard Cadillac User Experience for the CT6 allows the driver and passengers access to select programs on their smartphones, including reading text messages aloud, playing internet radio stations and other connected activities without taking their eyes off the road or their hands from the wheel. The S8 doesn’t offer factory integrated smartphone program access.

The CT6 Luxury/Premium/Platinum has a 115-volt a/c outlet, allowing you to recharge a laptop or run small household appliances without special adapters that can break or get misplaced. The S8 doesn’t offer a house-current electrical outlet.

The CT6 Luxury/Premium/Platinum’s Automatic Park Assist can parallel park or back into a parking spot by itself, with the driver only controlling speed with the brake pedal. The S8 doesn’t offer an automated parking system.

Economic Advantages Comparison

Insurance will cost less for the CT6 owner. The Complete Car Cost Guide estimates that insurance for the CT6 will cost $6745 to $8155 less than the S8 over a five-year period.

IntelliChoice estimates that five-year ownership costs (depreciation, financing, insurance, fuel, fees, repairs and maintenance) for the Cadillac CT6 will be $54758 to $59622 less than for the Audi S8.

Recommendations Comparison

The Cadillac CT6 outsold the Audi A8/S8 by over two to one during 2016.

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