Spied: 2012 Audi S8 - 450 hp, twin-turbo V8 for Audi's flagship S

Car and driver reports today that Audi will debut an all-new S8 for the 2012 model year - with spy shots to prove it. According to C&D, the 2012 Audi S8 will be powered by a new 450 horsepower, twin-turbocharged, 4.0-liter V8. The twin-turbo V8 will match the previous generation's V10 horsepower figures but will reportedly develop much more low-end torque with less fuel consumption than the V10.

In addition to the 450 hp, twin-turbo V8, Audi will also offer a 400 horsepower configuration featuring a single turbocharger. The 400 hp 4.0L V8 will replace the A8's current 4.2L V8 and will also power the new S7 (yes, there is already an S version planned for the A7 Sportback).

It's also worth noting that although Audi's S and RS models are usually the most powerful versions of any given model, this will not be the case with the S8. The Audi A8 W12 will be the most powerful A8. Boasting 500 horsepower, the 6.3-liter W12 powered A8 is set to launch this fall.

Be sure to visit Car and Driver to see the full gallery of 2012 Audi S8 spy photos.