While Audi already sells Sportback (Audi-speak for a 4-door coupe) versions of the A5 compact executive car and the sportier S5, the RS 5 arrives as a new, more hardcore addition to the lineup. Consider it an RS 5 coupe, but with 2 extra doors, 2.3 extra inches of length, about an inch of extra height, and less than 100 pounds of extra weight despite all that added practicality. Visually, it stands out from lesser Sportback Audi A5 and S5, thanks to more aggressive styling at the front end. Under the hood, it stands out with lots of extra punch from the twin-turbo V6 out of the Porsche Panamera 4S. The RS 5 Sportback’s V6 is a 2.9-liter unit with 444 horsepower and 443 pound-feet of torque, which Audi claims will get the RS 5 Sportback to 60 mph in just 3.8 seconds. This is thanks in large part to the company’s famous quattro all-wheel-drive (AWD) system and an 8-speed Tiptronic automatic transmission. Top speed is limited to 155 mph, but an available Dynamic Plus package allows for a 174-mph top speed. That same Dynamic Plus package also adds carbon-ceramic front brakes. The Dynamic (non-Plus) package adds sport suspension with Dynamic Ride Control and a sport exhaust. All RS 5 Sportbacks come with adaptive dampers, and the AWD system can put more power to the rear than normal in certain situations for more of a rear-drive feel. The RS 5 Sportback also returns 17 mpg city, 26 highway, and 20 combined with premium fuel. On the inside, the RS 5 Sportback gets 21.8 cubic feet of rear storage space that expand to 35 cubic feet with the seats folded. The Sportback features the usual mix of sporty touches and high-end luxury, including a flat-bottom steering wheel, a 12.3-inch digital instrument cluster, well-bolstered seats, and an 8.3-inch infotainment screen that comes with Apple CarPlay and Android Auto. Nappa leather upholstery and an upgraded stereo by Bang & Olufsen are among the more tempting extras. The RS 5 Sportback is also available with automatic high-beam headlights, adaptive cruise control, lane-keep assist, a head-up display (HUD), and self-parking assist. The Audi RS 5 was already a usable, livable luxury car that could also enjoy a double life as a high-performance coupe capable of running with more focused sports cars, but the new Sportback adds practicality to the lineup while sacrificing very little speed.