Used 2015 Audi A8 3.0T quattro Sedan Review

The Audi A8 receives a few updates for 2015 that include revised front-end styling with standard LED headlights, a bit more power for the A8 4.0T, a lane-keeping assist feature and a head-up display.

The 2015 Audi A8 remains one of our top luxury sedan picks for its high levels of comfort, performance and numerous high-tech features.

When it comes to flagship luxury sedans, models from Germany have dominated the segment for some time now. It's also true that within that group the BMW 7 Series and Mercedes-Benz S-Class have traditionally enjoyed the lion's share of popularity. But the 2015 Audi A8 could very well change people's perceptions, as it has all the right qualities expected of the class while also endearing itself to drivers who enjoy a sense of connectedness with the road.

Go with an Audi A8 and you'll be getting a supremely luxurious interior, top-of-the-line materials and an abundance of high-tech features. As with other luxury sedans in this class, the A8 provides ample power throughout the lineup, but it stands out for its appeal as a driver's car. Thanks to standard all-wheel drive, the A8 is blessed with confident road manners and tenacious grip on a winding mountain road. It may be a big sedan, but it won't necessarily seem like that when you're behind the wheel.

Usually, sharp handling capabilities come at the expense of ride comfort, but the A8 has no such shortcoming. It rides just as smoothly as its rivals and adequately isolates the passengers from the harshness of the outside world. Whether it's performing daily commuting duties or transporting lucky passengers on a lengthy road trip, the A8 offers many amenities and cosseting comfort that make it worthy of consideration as one of the best in its class.

But the competition is fierce. Mercedes-Benz has rolled out an all-new 2015 S-Class, which packs in even more technology, but does so with an old-world charm consistent with its heritage. The 2015 BMW 7 Series is also a perennial top pick, but as it enters its sixth year since a major redesign, it has fallen ever so slightly behind the times. For the rare driver who craves even more performance than the Audi delivers, the 2015 Porsche Panamera should get his or her blood racing, along with the sleek and unapologetically British 2015 Jaguar XJ. The good news for you is that you're a winner no matter what you pick. But we're very fond of the Edmunds "A" rated Audi A8 and certainly recommend comparing it to the established favorites in this class.

The 2015 Audi A8 is a large luxury sedan that is available in either normal or long-wheelbase versions for the six- and eight-cylinder gasoline-powered models. Diesel-powered TDI models and the range-topping W12 are available only in the long-wheelbase body style.

The base A8 3.0T trim is appointed with 19-inch wheels, LED headlights, a sunroof, heated and power-folding exterior mirrors, auto-dimming mirrors, front and rear parking sensors, power door closers, an adaptive air suspension, keyless ignition and entry, dual-zone automatic climate control, leather upholstery, 14-way power adjustable front seats (with four-way power lumbar), front seat memory functions, a power tilt-and-telescoping steering wheel and a power rear sunshade. Electronic features include in-car WiFi, an 8-inch display screen, Bluetooth phone and audio connectivity, Audi's MMI infotainment interface, a navigation system, voice controls, a rearview camera and a 14-speaker Bose surround-sound audio system with a CD player, iPod connectivity and satellite radio.

The eight-cylinder A8 4.0T includes all of the above plus interior active noise cancellation. Opting for any of the long-wheelbase versions adds the Warm Weather package (four-zone automatic climate control and power rear side sunshades), the Extended Leather package (leather-upholstered door armrests, center console and airbag cover), rear seat vanity mirrors and LED reading lights.

The long-wheelbase W12 further adds 20-inch wheels, a panoramic sunroof, dual-pane acoustic glass, variable-ratio steering, premium leather upholstery, a simulated suede headliner, a head-up display, a surround-view camera system, a blind-spot monitoring system, a dual-screen rear seat entertainment system and a six-CD changer. Also included are the Cold Weather package (heated steering wheel, a rear seat cargo pass-through and heated rear seats), the Rear Seat Comfort package (separate rear power-adjustable outboard seats and rear seat ventilation with massage) and a fixed rear seat center console that reduces passenger capacity from five to four.

Many of the items featured in upper trims are available as packaged options in supporting models. Other notable add-ons include adaptive cruise control, a sport differential, enhanced steering, automatic high-beam control, night vision with pedestrian and animal detection, a lane-departure warning and keeping system, a sunroof with solar panels that power an auxiliary cooling fan, ventilated 18-way power-adjustable front seats, sport seats with diamond-stitched upholstery and a 19-speaker Bang & Olufsen surround-sound audio system. A variety of interior wood trim accents are also available.

In A8 W12 trim, additional options include the Executive Rear Seat Comfort package, which includes a power foot rest for the right rear passenger, a cool box in the rear center console and a household-type power outlet.

Powering the 2015 A8 3.0T is a supercharged 3.0-liter V6 engine that produces 333 horsepower and 325 pound-feet of torque. As with all A8 models, the 3.0T channels power to all four wheels through an eight-speed automatic transmission. In Edmunds testing, this model reached 60 mph in a short 5.3 seconds, which is quicker than other six-cylinder-powered rivals and almost as quick as some V8s. EPA fuel economy estimates for the A8 vary depending on which engine you opt for, but the 3.0-liter V6 gets an estimate of 22 mpg combined (19 city/29 highway).

The diesel-powered A8 TDI utilizes a turbocharged 3.0-liter V6 that's good for 240 hp and 428 lb-ft of torque. Audi estimates it will accelerate to 60 mph in 6.3 seconds. EPA-estimated fuel economy comes in at 28 mpg combined (24 city/36 highway).

Audi A8 4.0T models receive a turbocharged 4.0-liter V8 engine that makes 435 hp and 444 lb-ft of torque -- an increase of 15 hp over last year. Audi estimates it will get to 60 mph in 4.3 seconds (4.4 with the long wheelbase). Fuel economy is estimated at 22 mpg combined (18/30) for the normal-wheelbase model. Long-wheelbase versions are estimated to get 1 fewer mpg on the highway.

The range-topping A8 W12 produces 500 hp and 463 lb-ft of torque from its 6.3-liter normally aspirated W12 engine. Audi expects it to reach 60 mph in 4.4 seconds, while fuel economy estimates drop to 17 mpg combined (14/22). Unlike other A8s, the W12 does not benefit from an automatic engine stop-start function to conserve fuel while not in motion.

Standard safety features for all 2015 Audi A8 models include antilock brakes, stability and traction control, front and rear side airbags, front knee airbags, full-length side curtain airbags, a rearview camera and Audi's Pre-Sense system that pretensions seatbelts and closes the sunroof and windows if it detects heavy braking.

Models equipped with the adaptive cruise control option also come with Pre-Sense Plus, which alerts the driver to imminent frontal collisions and intervenes with maximum braking if appropriate action is not taken. Also included is Pre-Sense Rear, which reacts to imminent rear-end collisions by tensioning seatbelts, closing windows and adjusting the seats for optimal protection. Other features that may be standard or optional depending on trim level include a surround-view camera system, a night vision system, a lane-departure warning and lane-keeping assist system and a blind-spot monitoring system.

In Edmunds brake tests for previous-year but mechanically similar A8s, models equipped with summer tires came to a stop from 60 mph in distances shorter than 104 feet, which is exceptional for cars in this class. With all-season tires, those distances increased to 114 feet, which is also excellent.

Considering the V8 engine's abundance of power and its nearly identical fuel economy estimates to the V6, it's our preference among the gasoline-powered A8 models. Either engine is perfectly capable in terms of acceleration and braking, but the V8 gets up to speed and passes slower traffic with a flood of power and minimal effort. The same holds true for the diesel-powered A8 TDI, thanks to its wealth of torque. There's very little clatter coming from the engine, though the automatic stop-start function can be a little jarring. Thankfully, it can be disabled easily.

All 2015 Audi A8s come with all-wheel drive that provides high levels of cornering prowess and surefootedness on slick roads. Furthermore, the well-tuned suspension and intuitive steering response allow the big sedan to corner like a much smaller car. For drivers who have higher expectations for performance, the A8 should satisfy their preference for power and handling.

Despite the A8's sporting capabilities, it still delivers the kind of unruffled comfort that you'd expect from a flagship luxury sedan. Rough pavement is smoothed over with uncanny ease and the cabin remains as quiet as a crypt over a variety of surfaces and at highway speeds. For these reasons, the 2015 Audi A8 distinguishes itself from rivals by delivering world-class comfort while providing better-than-average driver engagement.

Among large luxury flagships, interiors are arguably one of the most important deciding factors. The 2015 Audi A8 rises to the occasion with excellent materials, smart design and an abundance of high-tech features. Most Audis are notable for their businesslike austere design, but the A8 is decidedly luxurious in its execution, using rich wood accents and supple leather surfaces to complement it.

Comfort is in no short supply, even with the standard 14-way adjustable front seats. Upgrading to the optional 18-way adjustable ventilated seats further enhances passenger satisfaction, and the massage functions should be enough to send most people over the edge (although certain competitors also offer them). That same level of decadence can also be enjoyed in the rear seats by upgrading to the Rear Seat Comfort package for long-wheelbase versions. Even without that option, rear passengers enjoy a wealth of space and amenities.

Audi's MMI infotainment interface should also meet the high expectations for the class with sharp graphics and quick responses to inputs. There's also a small pad on which you can trace letters and numbers with your fingertip to enter addresses or search for phone numbers and music. On the whole, the system isn't as easy to operate as those of rivals, but after a short time it should become second nature.

On the downside, cargo capacity is on the small side compared with the competition, accommodating a maximum of only 14.2 cubic feet.