Compared to the Audi A8 that was spied on the Nurburgring Nordschleife in the middle of June, the S8 features four exhaust tips out the back, different headlight internals, and a beefier braking package.
The S8 prototype seen here has drilled brakes at both ends, with S-branded callipers up front. Oddly, the S8's front fascia doesn't look any more aggressive than the one fitted to June's A8 prototype — expect that change as production nears.
Up front, they both sport a sharply defined six-point reimagining of company's single-frame grille, which is flanked by wedge-like headlamp units.
Given the A8's role in life as a stately upper crust sedan, it looks as though it will miss out on flared wheel arches and shoulder crease highlights that grace the new A7.
At this stage, it's not known what engine the new S8 will sport, although a version of the Porsche developed 2.9-litre twin-turbo V6 is possible. As currently employed in the second-generation Panamera, the 2.9-litre engine develops 324kW of power and 550Nm of torque.
The new A8 and S8 will use the Volkswagen Group's latest MLB component set for front- and all-wheel drive cars with longitudinal engines. In keeping with the A8's history, expect it to use plenty of aluminium.
Unlike earlier iterations of the A8, the new car may spawn an ultra-long wheelbase model, as well as a coupe variant.
Rumour has it that the new A8 will debut in the back half of 2017, meaning that it won't go on sale in Australia until 2018.
MORE: Audi S8 news and reviews