The fourth generation of the Audi S8 was unveiled at the end of 2019 and it brings a host of novelties compared to its predecessor, including the addition of a mild-hybrid system based on a 48-volt architecture.
Other than the mild-hybrid system, the twin-turbocharged 4.0-liter V8 is similar to the one found in the Audi S8 D4, but it has also received a couple of modifications, including iron-lined cylinder barrels positioned in an aluminum crankcase.

With 571 horsepower and 800 Nm (590 lb-ft) of torque on tap, sent to all four-wheel through a quattro all-wheel-drive system, the sporty luxury sedan can hit 100 kph (62 mph) from a standing start in just 3.8 seconds. Even though it also helps performance during spirited driving, the mild-hybrid 48-volt system actually works continuously to reduce fuel consumption, with up to 0.8-liters per 100 kilometers in fuel saving being possible thanks strictly to the system. The setup uses a 48-volt belt alternator starter and an additional lithium-ion battery. The braking system is truly high-performance, with the optional carbon-fiber brake discs measuring no less than 420 mm (16.5 in) on the front axle and 370 mm (14.6 in) on the rear axle while also being 9.6 kg (21.2 lb) lighter than the standard cast iron discs. No less than 38 driver assistance systems comprise the active safety systems on the new S8, and they are all managed by a new high-performance processing unit.