The rise of the SUV means the A6 sedan is not Audi's best-selling vehicle anymore; it's the Q5, followed by the Q7.

So why is the A6 so important to the German luxury group when the luxury midsize sedan segment is cratering? This fifth-generation A6, known internally as C8, matters because Audi thinks midsize sedans still matter, and driving dynamics in a sedan will never get old. A6 project leader Christian Konig describes A6 as the versatile soul of the brand—a car that offers comfort to the Europeans, sportiness to North America, and status in China.

See all 124 photos

See all 124 photos

We got our first drive in some European-spec A6s in the craggy hills of the Douro Valley about an hour from Porto, Portugal. These narrow roads contain a bounty of curves that would make California canyon roads envious—making it a perfect place to test Audi's performance claims. To wit: The A6 is more nimble than its predecessor while offering more tech and a more spacious interior by increasing the wheelbase; overall length grew only 0.8 inch.

Despite new sheetmetal, the look is not a big shift from the outgoing model. It adopts the front end of the A7 with a grille that is wider and lower. There's also a new chrome line across the rear that connects the taillamps and makes the car look wider.

Built in Neckarsulm, Germany, the 2019 A6 launches with a trio of 3.0-liter turbocharged V-6 engines: a gasoline V-6 that generates 340 horsepower and 369 lb-ft of torque for North America, plus two diesels with varying outputs, which America does not get. The current gasoline V-6 has a supercharger, but Audi is going turbo with this engine series. Audi says the gas V-6 will go 0-62 mph in 5.1 seconds.

See all 124 photos

All the 3.0-liter engines are mild hybrids with a standard 48-volt system: a belt-alternator starter with a lithium-ion battery. The gas engine is paired with a seven-speed S tronic dual-clutch transmission, though the diesels partner with an eight-speed automatic. Power can surge a bit when you stomp on the gas at lower speeds, but it is a nice, smooth delivery at higher speeds. Quattro all-wheel drive is standard with a self-locking center differential.

The A6 goes on sale in America this fall. After the first model year Audi will add 2.0-liter four-cylinder gas and diesel engines, and China gets an A6L down the road, but timing for these variants is not set. Further down the line, there could be a four-cylinder hybrid or even a plug-in hybrid. A pure electric A6 won't happen in this generation.

See all 124 photos

There are a number of suspension offerings: steel spring, steel spring with damper control, sport suspension with steel springs, and adaptive air suspension with controlled damping. The U.S. does not get the air suspension option—although it might show up on the S6. We get the steel suspension with hydraulic adjustable dampers and the sport suspension with stronger steel springs.

Don't feel too bad. The difference between the steel and air suspensions was barely perceptible. Then again, our drive was on smooth roads. The few patches of rougher pavement we found were easily sopped up by both suspensions. The car experienced little body roll on those twisting roads.

Per typical Audi, drive modes include Efficiency, Comfort, Auto, Dynamic, and Individual, which allow for adjusting the steering, dampers, and transmission shift points.

Portugal's smorgasbord of winding roads showed off Audi's all-wheel steering, where the rear axle steers in the opposite direction for a tight turning radius. We can attest to its efficacy from a number of dicey turnarounds on narrow roads we experienced, when the navigation system suggested a questionable route down a narrow cobblestone road with a slope fit for a goat. On straight stretches, having both sets of wheels in line increases stability and tracking. Having said all that, the U.S. does not get the rear steering. It's being saved for the S6.

See all 124 photos

It makes a difference. With standard steering, the steering wheel does feel heavier and slightly less responsive to touch. But it does react well, being neither dead nor flighty.

There are up to 39 driver-assist technologies, including adaptive cruise with traffic jam assist. Should traffic clear and you set your cruise speed above the posted limit, the instrument panel flashes the limit with an exclamation mark to visually spank you for flouting the law.

There also is the usual assortment of steering, accelerating, and braking assists to keep the car in the lane and with traffic. The ability to read narrow spaces is new, with the car's more elaborate array of sensors, radars, and cameras able to better read the surroundings and calculate the center of the lane—as opposed to reading the sides of the lane (or road) and ping-ponging within those boundaries. However, the sensitivity of the lane keep assist was set high on the cars we drove, resulting in an aggressive correction. We are told it will be softened up for the U.S. The pre-collision warning was also set to the max, and many of us experienced sudden warning and braking when it was not truly justified. Again, the settings could change for the U.S. market.

See all 124 photos

Cameras provide a 360-degree view around the car to check for a parking garage column lurking in a blind spot or to prevent curbing a wheel when parallel parking. We also found a new use for the system when the navigation sent us down the aforementioned narrow goat paths, where the ground vanished below the hoodline in a manner more associated with off-roading a Jeep. We used the feature to ensure we kept an inch clear on each side of the car—especially as we had to turn off the apoplectic parking sensors.

Open the soft-closing door, and you will find comfortable new seats that are ventilated and have a choice of massage settings: not too soft, not too hard, just right. It has an air ionizer with cabin fragrance and soothing ambient lighting. We clambered into a Euro-spec interior with full leather seats and wood trim that essentially matches what we get in the U.S. It's tastefully done, with a mix of modern, business, and cozy. The cabin is quiet with little road or engine noise wafting inside.

The car can store up to 400 settings for seven people for an eminently customizable driving experience—that is a lot of computing power. A panoramic sunroof will be standard. It has more legroom front and back, trunk space is wider, and you can wave your foot to close the trunklid when your arms are full.

See all 124 photos

The A6 has Audi's acclaimed Virtual Cockpit as an optional feature, with its 12.3-inch screen and buttons on the steering wheel to control essential navigation, music, and telephone information. More information is readable on the head-up display. Voice command recognizes natural language such as "I'm hot" to prompt the system to ask if you want the temperature turned down.

Much effort was spent on the sixth-generation MMI touch response user interface. Using haptic touch, the icons on the center console top screen can be moved around and customized like on an iPhone. You also can pinch and zoom the perspective. There is a 10.1-inch top screen on the Premium Plus and Prestige trim levels, but it is 8.8 inches on the base Premium.

All trims have an 8.6-inch center console bottom screen for climate control and convenience functions with shortcuts for phone numbers, radio stations, and destinations. There is a choice of a keyboard to enter a destination or a pad to write what you want. And no more writing a single letter at a time—go crazy with full names or your craving for sushi. However, the screens smudge quickly with your fingerprints.

There will be standard navigation with six map updates over a number of years, as well as an upgraded nav system with the Connect package, which is free for the first six months, and a choice of online services. The Bang & Olufsen audio system is optional, and the A6 features online radio with thousands of stations from around the world.

See all 124 photos

Like so many of the modern interfaces, there are more functions than many owners will ever use. That's luxury for you. At times it seems like there are too many layers to access a simple function, but in many cases, once something is customized and set, the driver need not worry about it anymore. One instance: going to the top screen to find the menu to control the climate in the rear seat, which opens the controls on the bottom screen. There is a screen in the rear seat for those passengers to make their own adjustments, as well.

Not sure if this a deal-breaker, but Europe gets remote start; the U.S. does not. Canada gets a remote heater to preheat from the battery.

See all 124 photos

Apple CarPlay and Android Auto is compatible in a car that is always online with its integrated SIM card. There's wireless charging. A nice touch: A voice reminded us "your mobile is still in the car" when we were about to leave while the phone was charging in the center console, out of sight.

The more we think about it, Konig might be right: This is a versatile car, asked to be many things to many people. Our first drive shows it is up to the task.