To compete with the BMW M5 and the Mercedes-Benz E63 AMG Jaguar had to enter the horsepower wars being waged by the two top-tier German automakers. With 510 hp the XF-R falls right between the two—less than the E63's 525 hp and more than the M5's 500 hp. Paired with Jaguar's six-speed ZF transmission, the supercharged 5.0-liter engine is as smooth as it is bat-shit crazy. The engine can be docile and quiet when you want it to be, giving you power only when you want it. However, when you do want it, and the tranny kicks down a gear, things get wild. But it's the ability when the wildness can go away that's amazing. Most supercharged beasts chug along on regular roads like a pitbull waiting for its owner to slip up and drop its leash. It's a potentially tiring experience—but it that doesn't happen in this Jag.