Audi A8

The Audi A8 is a full-size luxury car built by the German automaker Audi to replace the V8 model as its flagship offering. Although the Volkswagen Phaeton, long wheelbase Jaguar XJ8 and Lexus LS 460 compete in the same size and price category as the A8, the Mercedes-Benz S-Class and BMW 7 Series are often thought to be its primary rivals. On the market since 1994, it has fully established itself as a popular alternative to these long-running competitors. Most versions feature Quattro all-wheel-drive as standard as well as a multitronic or tiptronic automatic transmission.

In 2001, Audi introduced in the U.S. market an S8 variant in the vein of Mercedes-Benz AMG models. Although it shared the standard model's platform, it featured a re-tuned, 360 PS (265 kW) version of the standard V8 engine, a re-tuned suspension with larger wheels and upgraded tires, enlarged brakes and a re-calibrated version of the 5-speed Tiptronic transmission (European-spec. models had a 6-speed manual transmission option); quattro was standard. Production of the first-generation S8 ended in 2003, shortly before the introduction of the D3 platform A8.
In the last quarter of 2005, Audi introduced a new S8, now powered by a 450 PS (331 kW) V10 engine derived from the 5.0 L V10 used in the Lamborghini Gallardo. Much public confusion surrounded this engine choice after Audi's initial announcement because its power output is identical to that of the W12 motor, prompting people to ask why Audi would bother with the development of the V10.

However, Audi claims that the V10 revs more quickly than the W12, and that its lighter weight helps give the S8 a lower overall curb weight and better weight distribution (the SWB model being 20 kg lighter). Initial reviews from European automotive magazines seem generally positive.
Audi's factory performance claims for the V10 S8 indicate a 0-100 km/h time of 5.1 seconds. This would put it in a competitive range with the Mercedes-Benz S 55 AMG and the S600 (powered by a twin-turbo V12), the BMW 760Li (powered by a naturally-aspirated 12 cylinder engine) and the company's own A8L W12, although the upcoming version of the Mercedes-Benz S65 AMG will be considerably faster, albeit at a much higher price.