Audi A8 review: This V-8 lightweight proves its mettle

Though you may not think of aluminum as a precious metal as you would gold, silver or platinum, the metal certainly had its heyday. Once scarce and valuable, it was prized by Napoleon III, shown at the Paris Exposition in 1855 and chosen to cap the Washington Monument in 1884.

After spending a week in Audi's flagship A8, I would argue that in an automobile, aluminum is still worth its weight in gold.

You see, the chassis on this $78,925 sedan (base price) is made from aluminum; the company calls it Audi Space Frame. The folks in Ingolstadt, Germany, have been building the A8's body this way since it introduced the luxo-barge in 1994.

But this latest chapter in the book of A8 also includes Audi Drive Select, a standard system that controls the vehicle's adaptive air suspension, the steering characteristics, transmission shift points and engine throttle response.

Drivers can choose from three progressively sportier settings, from "Comfort" to "Auto" to "Dynamic," or a fourth option in which drivers customize the settings.

Pair this system of electronics with the light weight of the aluminum construction, and the result is a full-size car that handles like a much smaller vehicle. Imagine Zenyatta's size and the agility of her jockey, Mike Smith.

The normal-wheelbase A8, with the standard Quattro all-wheel-drive system, weighs in at 4,409 pounds. That's at least 200 pounds lighter than all-wheel-drive versions of its main rivals, the BMW 7 Series and the Mercedes Benz S-Class.

You feel this difference as you hustle the Audi through turns, and if it were my signature on the check, the A8 would be my preference. The car remains planted, stable and precise, even if you bite off more corner than you can chew. Only when you push the A8 to its limits does the car's nose-heavy setup start to understeer.

The A8 is powered by a 4.2-liter V-8 good for 372 horsepower and 328 pound-feet of torque. The engine is largely a carryover from the previous A8 and puts the car at the bottom of its class for output, though you wouldn't know it as you pull away from a stoplight.

Power application is magnanimous and linear, and the Audi gets from 0 to 60 mph in a scant 5.7 seconds. Much of the credit for this performance goes to the all-new eight-speed automatic transmission with sport mode and paddle shifters, though the vehicle's light weight pays dividends here too.

Further benefits from the curb weight are noticeable with the A8's fuel economy. The car is rated 17 miles per gallon in thecity and 27 mpg on the highway, and its 21-mpg combined rating ties with Mercedes and Lexus hybrids for best in class efficiency. I saw just over 21 mpg in more than 400 miles of less-than-conservative driving.

Unfortunately, slowing down this sprightly A8 is harder than you think. A car this solicitous with acceleration should be equally eager to decelerate, yet the brakes on this Audi felt too soft and vague initially when the pedal was pressed.

Regardless of its speed, the front of the A8 is sure to attract attention.

The bold grille features prominent horizontal lines and is the most extreme take on Audi's corporate visage yet seen on a sedan. Meanwhile, the LED headlights also identify the A8 as an Audi and give the car an unmistakably dramatic appearance.

These design flourishes give way to a more conservative bent as you move to the rear of the car. This may be an effort by Audi to not interfere with the style of the forthcoming A7 Sportback sedan, but it means the back of the A8 looks like little more than a bloated A4.

Inside, the A8 continues to establish Audi as a leader in interior design and ergonomics, though it's not perfect.

The charisma of the A8's interior easily eclipses that of an S-Class or 7 Series, with broad swaths of brushed aluminum mixed with wood trim and suede inserts on the doors. Neither aesthetics nor practicality are sacrificed.

At the heart of the controls is Audi's Multi Media Interface through which drivers access nearly everything save for the heating and cooling. New to this version is a touchpad, on which drivers draw one (uppercase) letter at a time to spell out their destination for the navigation system.

The touchpad proved equal parts utility and novelty; it's an improvement over Audi's previous system wherein the driver must rotate a dial to select the letter or number, but for my money touch-screen systems are faster and easier.

The highlight of the interior in the particular $93,525 version I tested was the stereo system. Since I'm not an audio engineer, it's hard to describe the sound of the optional $6,300, 1,400-watt, 19-channel, 19-speaker Bang & Olufsen setup.

But a quick jaunt through " Led Zeppelin II" at full volume reveals there are notes, layers and tones to "Whole Lotta Love" you've probably never heard before. It's as if Robert Plant and Jimmy Page are shoveling mind-altering caviar into your eardrums.

The biggest downside to the A8's interior was trying to get the car to go backward.

German luxury automakers seem to have a gentleman's bet on who can reinvent the shift lever, and Audi's attempt in the A8 is fine until you try to put the car in reverse. The leather-topped shift knob resembles the head of a golf putter and is nicely positioned to rest your hand on when spelling out your destination on the touchpad.

Yet the indentations to denote park, reverse, neutral and drive are minute enough to regularly miss reverse. A week of using the car yielded no improvement on the learning curve.

The $78,925 base price on the A8 easily undercuts its BMW and Mercedes Benz peers by several thousand dollars, though the options add up quickly.

All told, the car is lighter on the road, lighter on your gas mileage and lighter on your wallet. Napoleon III would be jealous.