With its 450-hp 4.2-liter V-8 engine, quick-acting dual-clutch transmission, and torque-vectoring Quattro all-wheel drive, the RS5 is the most exciting version of Audi’s A5 coupe to date. It’s also the heaviest version, scaling at 4009 pounds — more than 300 pounds heavier than the regular Audi A5. Yet the weight doesn’t hold back the Audi’s performance potential. In a recent comparison test, it lapped Michigan’s Grattan Raceway quicker than a BMW M3, Porsche Boxster S, and Mercedes-Benz C63 AMG. The A5 and S5 coupes have less power, but still reward owners with a sporting driving experience wrapped in a sultry design. The A5 and S5 were mildly refreshed for the 2013 model year, with upgrades including new headlights, a new grille, electric power steering, more infotainment toys, and a supercharged 3.0-liter V-6 in place of the car’s previous 4.2-liter V-8. The base A5 coupe weighs 3681 pounds, while the S5 is 3858 pounds with a six-speed manual transmission and 3924 pounds with its optional seven-speed dual-clutch.