For speed freaks with a penchant for comfort and luxury, there's few flagship sedans that do it as well as the 2021 Audi S8.
With a twin-turbocharged V-8 quietly toiling away under the hood, the S8 can effortlessly blast you and three others to high speeds. And when the going gets twisty, Audi's big four-door can gobble pavement at an eye-opening pace.
Based on the more mellow A8 luxury sedan, the S8 receives a performance suspension, upgraded brakes, and a punchier power-train, but its exterior styling barely whispers "high-performance"—which makes it a stealth bomber for the road.
Inside, the S8 offers just as much space and as many creature comforts as rivals such as the BMW 7-series and the Mercedes-Benz S-class, including massaging front and rear seats, the latest in infotainment features, high-quality materials, and excellent fit and finish.
The S8's sole engine choice is a potent one: a twin-turbocharged 4.0-liter V-8 engine making 563 horsepower and 590 lb-ft of torque. All-wheel drive is standard, and the transmission is an eight-speed automatic.
Audi claims a top speed of 155 mph, and there are fuel-saving systems, too, including cylinder deactivation and a mild-hybrid setup with a small electric motor and battery. The S8 goes from 0 to 60 mph in just 3.2 seconds.
An active suspension system can control each wheel individually to improve ride quality, and it is tuned differently than that of the standard A8, promising improved cornering prowess thanks to reduced body roll.
Audi also includes equipment such as a torque-vectoring rear differential and rear-wheel steering to increase agility; powerful carbon-ceramic brakes are optional.
Even though the S8 is technically a hybrid, buyers shouldn't expect Toyota Prius-level fuel efficiency. The EPA estimates that the best we can expect is 22 mpg on the highway, with the city rating dropping down to just 13 mpg.
The front seats offer standard heating, cooling, and massage, while the rear cabin offers tons of space for passengers to stretch out.
To pamper those in the back seat even more, consider the Rear Seat Comfort package, which adds power-adjustable outboard seats with heat, ventilation, and massage, plusher headrests, heated armrests, and a remote control for the car's infotainment system.
Four-zone automatic climate control is standard, as is a multi-color ambient interior lighting system.
The trunk is generously sized and identical to that of the A8, which proved its mettle in our testing by holding six carry-on suitcases. For comparison the S-class held 5 and the 7-series held just three.
As with the standard A8, the S8's interior is a rolling tech showpiece. Multiple touchscreens control climate, audio, navigation, and myriad connectivity functions.
Audi's 12.3-inch Virtual Cockpit digital gauge cluster is standard, as is a 10.1-inch upper infotainment system and an 8.6-inch lower display.
Apple CarPlay, Android Auto, an on-board Wi-Fi hotspot, and in-dash navigation are all standard, and occupants can charge their compatible smartphones wirelessly using the S8's charging pad. Audiophiles will be happy to find that a 17-speaker Bang & Olufsen system is standard; for $5900, Audi will substitute a 23-speaker setup.