The S8 is the mechanically-upgraded, high-performance version of the Audi A8, fitted standard with Audi's quattro all-wheel drive system, and was only offered with a short-wheelbase for the first three generations, being joined by a long-wheelbase variant option for the fourth generation.

In 1999, the car was updated with a power increase to 369 PS (271 kW; 364 hp), which brought the 0–60 mph (97 km/h) acceleration down to 5.6 seconds.

The car was equipped with a modified V10 engine shared with the Lamborghini Gallardo of the same years.

In 2016, the S8 plus version was launched with an increased engine power of 605 PS (445 kW; 597 hp).

[6][7] Unlike the regular S8 which was built by Audi on the regular assembly line alongside other A8 variants, the S8 Plus was built by Audi Sport (formerly Quattro GmbH) and has a VIN that starts with WUA to identify it.

[10] The S8 is now the flagship of the Audi A8 range, since the nominally higher-end A8 L W12 was no longer offered after the 2018 model year.