That Audi would launch the fire-breathing S8 to compete with German mega-sedans, including the Mercedes-Benz S63 and the BMW Alpina B7, isn't a surprise.
That the S8 would provide a viable alternative to its distant cousin -- the Porsche Panamera Turbo -- is. And it does this for $30,000 less.
The S8 is the latest S model from Audi. It sits atop the brand's hierarchy of sedans and coupes; only the R8 V-10 supercar has more horsepower. The full-size sedan joins the recently introduced S6, S7 and RS5, giving Audi a compelling mix of competitors to take on Mercedes' AMG line and BMW's M series.
Photos: 2013 Audi S8
Though it looks nearly identical to the A8, the S8 distinguishes itself under the hood, with a 4.0-liter, twin-turbocharged V-8 making 520 horsepower and 481 pound-feet of torque. Like the A8, the S8 has an eight-speed automatic transmission that routs power to all four wheels via Audi's full-time Quattro system.
Other notable upgrades include a sport-differential, sport-tuned adaptive air suspension and larger disc brakes. The extra kit adds about 100 pounds to the A8's curb weight, a substantial 4,641 pounds.
Despite the weight gain, the S8 blows through zero-to-60 mph in a mere 3.9 seconds, according to Audi. That clobbers the relevant Mercedes and BMW competitors, which clock in at 4.4 seconds and 4.3 seconds, respectively. It even tops the Porsche's 4.0-second time.
When not stomping the egos of rival German power-sedans, the S8 uses cylinder deactivation to return fuel economy of 15 miles per gallon in the city and 26 mpg on the highway. But in 300 miles of combined city and highway driving, we saw 14.9 mpg.
That low figure may result from some regular mashing of the go pedal -- hard to resist in the S8. Pushed on the open freeway, the S8 rears back on its haunches, downshifts a couple of gears and shoots forward with a velvety roar.
Though this Audi doesn't have the dual-clutch gearbox of the S6 and S7, you wouldn't know it from the S8's crisp shifts. Also surprising is how this large car shrinks around the driver when the roads get twisty. The air suspension adroitly minimizes body roll, and it pairs with the all-wheel drive for a neutral yet communicative feel. This S8's grip could pull the tar off the roadway.
Entry to this rarefied segment is made easier by Audi's relatively low base price. $110,895 could buy you a lovely starter home in much of the country, but it won't get you into the aforementioned Mercedes, BMW or Porsche.
The Daytona Grey model we tested added options including a $6,300 Bang & Olufsen stereo system and an overpriced $5,500 full-leather package. With an out-the-door total of $125,995, the 2013 Audi S8 still counts for a bargain in the super-sedan segment.