German automaker Audi expands its high-performance RS line for 2014 with the addition of the Audi RS 7 Sportback. Based on the sleek, well-proportioned Audi A7, the RS 7 4-door hatchback (Audi calls it a 5-door coupe) continues the tradition of high-end, track-tuned RS-designated vehicles, which dates back to 1994, when the first RS, the Audi RS 2 Avant, was unveiled. The 2014 RS 7, which debuted at the 2013 North American International Auto Show in Detroit, features unique exterior styling, an innovative 560-hp twin-turbo V8, quattro permanent all-wheel drive (AWD), standard 20-inch wheels and a large, comfortable cabin with sport seats and high-end trim and finishes. Outside, a number of RS-specific features distinguish the RS 7 from the standard A7/S7, including a unique front end with a wide-mouthed black mesh honeycomb grille, a large lower air intake, a lower splitter and diffuser, a distinctive bumper and LED automatic headlights with LED daytime running lights. Subtle, flowing lines stretch from front to rear, and a lowered cabin line and fastback body style give the RS 7 a sporty appearance. At the rear, such features as a power-extending spoiler, a diffuser and dual elliptical tailpipes come standard. Completing the look are 20-inch forged lightweight wheels with a 7-twin-spoke design, although Audi offers optional 21-inch cast wheels in three designs. Buyers can choose from Matte Aluminum or Carbon exterior styling packages, as well as 10 exterior colors. Under the hood, Audi equips the RS 7 with its most powerful engine to date. Although physically it's relatively small at just 4 liters (3,993cc), the highly efficient TFSI twin-turbo V8 generates 560 hp, available between 5,700 and 6,700 rpm, and an impressive 516 lb-ft of torque from 1,750 to 5,500 rpm. Audi achieved these numbers by reconfiguring the cylinder heads and twin-scroll turbochargers to shorten the internal gas paths for improved response. The V8 also receives an RS-specific engine management and intake system for optimal performance. In addition, a start/stop system deactivates 4 cylinders when not required, so the engine operates as a 4-cylinder powerplant around town, when cruising or when stopped to help improve fuel economy. Audi says this transition happens smoothly and almost instantaneously and is rarely noticed by the driver and passengers. As a result of these technologies, the V8 manages decent fuel economy, averaging 24 mpg, although the EPA has not yet released its official city/highway mileage numbers. Audi pairs the V8 with an 8-speed Tiptronic automatic transmission with Normal and Sport modes, as well as a manual-shift mode with steering-wheel-mounted paddle shifters. The long 8th overdrive gear helps to conserve fuel, but thanks to closely spaced lower gears, the RS 7 officially jumps from 0-60 mph in just 3.9 seconds. Audi limits the car's top speed to 155 mpg, although the automaker offers a Dynamic Package that raises the top speed to 173 mph and a Dynamic Package Plus, which hikes it to 189 mph. The RS 7 comes standard with Audi's quattro AWD system, which includes an oil-cooled center differential. Under normal operation, the system distributes power 40/60 front-to-rear, but it makes adjustments as needed, depending on road conditions. Standard torque vectoring software works with the differential to ensure optimal handling in tight corners and at high speeds. Owners can opt for an available rear-axle sport differential, which uses two gears to distribute power to the wheels, as well as an optional adaptive air suspension system, which lowers the body by 0.79 inches at cruising speeds to improve handling, ride and fuel economy. It includes a driver-selectable adaptive damping system, which makes adjustments to the suspension to deliver a more comfortable or a firmer ride. Buyers can also add an optional sport suspension with Dynamic Ride Control, steel springs and 3-stage adjustable dampers. Electromechanical steering comes standard, although buyers can opt for available variable dynamic steering. Inside, the RS 7 features a large, comfortable cabin with a number of sport-oriented and RS-specific features, including a flat-bottomed leather sport steering wheel, a 200-mph speedometer, a tachometer with the RS 7 logo, black-faced gauges with red needles and an aluminum finish on the pedals and some controls. Black RS sport seats feature leather and Alcantara upholstery with diamond quilting, as well as supportive bolsters. Buyers can opt for honeycomb-quilted Valcona leather in black or silver, as well as power-adjustable comfort seats with memory. The RS 7 seats 4 passengers in a 2+2 arrangement. Cargo space checks in at 19 cubic feet with the rear seatbacks up, which expands to 49 cubic feet with the seatbacks folded down. A 5-inch pop-up touchscreen on the dash enables owners to manage the driver information and 10-speaker audio systems, as well as the optional Audi MMI navigation system. Three-zone automatic air conditioning, Bluetooth, keyless start, a power tailgate and cruise control are among the other standard features, while options include a heads-up display and a Bang & Olufsen Advanced Sound System, as well as a Comfort package. A full range of safety features includes a parking assist system, while optional safety systems include lane assist, side assist, a speed-limit display and a night vision assistant, which detects persons while driving in the dark. The standard electronic stability control system comes with a Sport mode and can be deactivated by the driver. Competitors to the RS 7 include the Mercedes-Benz CLS 63 AMG, the BMW M5, the Jaguar XF R and the Cadillac CTS-V sedan.