Buyers shopping for a highly advanced and very comfortable full-size luxury sedan have another choice for 2020 in the form of the all-new Audi S8. While this new fourth-generation S8 is the first to be available in both short- and long-wheelbase versions, North American buyers get only the long-wheelbase version. Under the hood of the S8 is a 4.0-liter twin-turbocharged 4.0-liter V8 with 563 horsepower and 590 pound-feet of torque. The engine works with Audi’s 48-volt Mild Hybrid technology, stop-start ignition, and cylinder deactivation in low-load situations for extra efficiency. Audi hasn’t quoted a 0-60 mph time, but top speed is electronically limited to 155 mph. A more powerful version may arrive in the near future. As of this writing, Audi hasn’t release fuel-economy figures. Dynamic all-wheel steering, adaptive air suspension, and a sport differential are standard on the new S8, as is predictive active suspension, which uses a camera on the front of the car to detect road-surface changes and then lifts or pushes down each wheel separately to reduce body roll during acceleration or braking. The all-wheel-steering system independently adjusts the steering angles at the front and rear axles, while the sport differential transfers torque between the rear wheels in the middle of a corner. Once it’s time to get out of the car, the A8's body can raise when the door handle is used, allowing for an easier exit. Being a full-size sedan and an Audi, the S8 does not sacrifice luxury in the name of performance. Active noise cancellation is standard, as is a head-up display (HUD) that projects information onto the windshield, and the leather-clad front seats feature diamond stitching, adjustable side bolsters, 3-stage heating, and both ventilation and massage functions. Audi’s latest MMI dual-screen infotainment system is another standout. Apple CarPlay, Android Auto, and a Bang & Olufsen 3D stereo are also standard. Adaptive cruise control, traffic-jam assist, and lane tracking are standard safety features. An optional Driver Assistance package adds what Audi calls its “pre sense 360” system. If the system detects an incoming side impact, it can tell the active suspension to raise the body by over 3 inches. The S8 sits at the top of Audi’s luxury performance sedan range above the S3, S4, S6, and S7. Other top-tier fast luxury sedans include the Mercedes-AMG S63, BMW Alpina B7, and Jaguar XJR.