Audi S8 - D4 (2011–present)

D4 (2011–present)

The D4-based Audi S8 4.0 TFSI quattro will go on sale as a 2013 model, after the 2011 Audi A8 and A8L and 2012 Audi A8L W12. Like the previous iteration, the upcoming S8 is expected to cost less than the A8L W12 which is positioned as the ultra-luxury model.

The S8 can accelerate from 0 to 100 km/h in 4.2 s. It is powered by a 4.0 litre TFSI biturbo V8 engine with 382 kilowatts (519 PS; 512 bhp) (128 hp per liter which is the highest in its class) and and 481-lb-ft of torque. The engine utilizes cylinder deactivation so it can run as a V4 for better fuel economy, with an Active Noise Cancellation system computerized engine mounts to suppress noise and vibration from fewer cylinders. The engine is mated to a Tiptronic eight-speed automatic with paddle shifters, as the S8 was meant to be more luxury-oriented than other Audi S models using 'S tronic, nonetheless the shifts from the torque converter are as quick as a dual-clutch.

The S8's engine is shared with the Bentley Continental GT where it makes 500 hp and 487 lb-ft. It will also be found in the 2013 model year Audi S6, Audi S7, and Audi A8 but mated to a seven-speed 'S tronic dual clutch transmission and detuned to 420-hp and 406-lb-ft (due to the maximum torque capacity of that gearbox). The upcoming Audi RS6 and RS7 will share the S8's engine, likely rated at 580 hp and 600 hp, respectively.

Direct competitors to the Audi S8 in the full-size luxury sport sedan segment include the 2011 BMW Alpina B7, 2012 Mercedes-Benz S63 AMG, and Porsche Panamera Turbo S, all of which also have twin-turbo V8 engines with direct injection. Although its official rated engine output is not as powerful than the ones of its rivals from BMW and Mercedes-Benz, the S8 makes up for this with a considerably lower weight as well as Quattro all-wheel drive providing grip for quicker acceleration (the B7 has optional xDrive all-wheel drive while the S63 is rear-wheel drive only). A comparison found that the Audi S8 had better handling and acceleration than the updated 2013 Alpina B7, even though the B7's 540 hp and 538 lb-ft of torque have it a 20 hp and 57 lb-ft advantage over the S8, making the S8. Another acceleration test found that the Audi S8 could match a Porsche Panamera Turbo S, although the Porsche is 200 pounds lighter with an additional 30 hp and a supposedly more responsive PDK dual clutch transmission.