Base 3.0-liter supercharged V6 has 333 horsepower; mid-range twin-turbo V8 now has 435 horses; boost is cranked to 520 horsepower for the S8; 12-cylinder and turbo-diesel V6 option reserved solely for the long-wheelbase models; eight-speed automatic transmissions.
While the S-Class remains the popular choice for enormous luxury machines, Audi’s changes to its 2015 A8 are aimed at attracting more buyers to the four-ring brand. While the exterior alterations are subtle, all A8s get new LED headlights, a more sculpted hood and Audi’s Singleframe grille, which is more textured than before. The A8 still comes in regular and extra-long L, which adds rear-seat-passenger stretch-out room. Notable is the vehicle’s pneumatic suspension; a computer is always changing the system to best absorb bumps on the road. There are no conventional springs of any kind, and you can even raise the long-wheelbase A8 enough to get through deep snow. Driver-operated systems, everything from entertainment to the suspension, are controlled through a console-mounted turn-and-push selector knob and a seven-inch screen on the dash, which is designed to also read the driver’s handwriting (for note-taking purposes) on a special panel. Base models still use Audi’s familiar 3.0-liter supercharged V6 with 333 horsepower. To bridge the gap between it and the long-wheelbase 500-horsepower 6.3-liter 12-cylinder, Audi uses a twin-turbocharged 4.0-liter V8 that now produces 435 horsepower (up from 420). Both the V6 and the V8 can be had in either body length, although speed freaks will appreciate the 520-horsepower version of the V8 in the short-wheelbase S8. For the fuel-conscious, the 3.0-liter turbo-diesel V6 has 240 horsepower and 406 pound-feet of torque, along with 24-mpg consumption in the city and up to 36 on the highway. Base gasoline A8s achieve 18/28. All models use an eight-speed automatic transmission (with manual control) and Quattro all-wheel-drive. While the regular V8 and 12-cylinder versions can hustle to 60 mph in 4.4 seconds, the lighter, more driver-focused S8 does it in 3.9. The S8 is more of “sleeper” than the hotted-up AMG products from Mercedes-Benz, although the 2015 version gets a more dramatic front bumper and grille, front air intakes, new side sills, and a rear diffuser that has even wider quad oval tailpipes. The standard driver-select package allows you to change the suspension, steering, transmission and differential settings between cushy soft and racetrack hard. The list of driver assistance systems is practically as long as the car, but some highlights include adaptive cruise control that can even stop the car on its own if it detects another vehicle in front doing the same, a night-vision camera that can now detect animals as well as pedestrians, and a system that keeps the car in its correct lane on the highway.