2009 Audi RS 6

When Audi’s performance arm quattro GmbH wanted to craft the next iteration of the RS6, the original car’s twin-turbo 4.2-liter V8 simply wasn’t going to cut muster with the BMW M5’s V10 on the prowl. What emerged from the Neckarsulum facility in Germany was a game-changer. Residing under the hood is a version of the V10 engine shared with the Lamborghini Gallardo and the Audi R8 supercar, but inhaling through a pair of turbochargers to produce an eye-watering 570 horsepower. Despite the V10 residing in these other cars, this is the most powerful version of the engine and the highest-rated output of any Audi thus far. Those turbochargers also provide a stark contrast to the supercharged or naturally-aspirated competition from the other German manufacturers, allowing the Audi to stand out not only for its remarkable thrust but also how that oomph is produced—an unrelenting wave of torque throughout the powerband.